{"id":103298,"date":"2024-07-18T08:07:30","date_gmt":"2024-07-18T06:07:30","guid":{"rendered":"https:\/\/www.linseis.com\/sem-categoria\/analise-de-materiais-termoelectricos-a-figura-de-merito-e-a-sua-medicao\/"},"modified":"2026-01-12T09:42:49","modified_gmt":"2026-01-12T08:42:49","slug":"analise-de-materiais-termoelectricos-a-figura-de-merito-e-a-sua-medicao","status":"publish","type":"post","link":"https:\/\/www.linseis.com\/pt-pt\/conhecimentos\/analise-de-materiais-termoelectricos-a-figura-de-merito-e-a-sua-medicao\/","title":{"rendered":"An\u00e1lise de materiais termoel\u00e9ctricos &#8211; a figura de m\u00e9rito e a sua medi\u00e7\u00e3o"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-post\" data-elementor-id=\"103298\" class=\"elementor elementor-103298 elementor-10431\" data-elementor-post-type=\"post\">\n\t\t\t\t<div class=\"elementor-element elementor-element-9eb8745 e-flex e-con-boxed e-con e-parent\" data-id=\"9eb8745\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-071d0c5 elementor-toc--minimized-on-tablet elementor-invisible elementor-widget elementor-widget-table-of-contents\" data-id=\"071d0c5\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;headings_by_tags&quot;:[&quot;h2&quot;],&quot;exclude_headings_by_selector&quot;:[],&quot;_animation&quot;:&quot;fadeInUp&quot;,&quot;no_headings_message&quot;:&quot;No headings were found on this page.&quot;,&quot;marker_view&quot;:&quot;numbers&quot;,&quot;minimize_box&quot;:&quot;yes&quot;,&quot;minimized_on&quot;:&quot;tablet&quot;,&quot;hierarchical_view&quot;:&quot;yes&quot;,&quot;min_height&quot;:{&quot;unit&quot;:&quot;px&quot;,&quot;size&quot;:&quot;&quot;,&quot;sizes&quot;:[]},&quot;min_height_tablet&quot;:{&quot;unit&quot;:&quot;px&quot;,&quot;size&quot;:&quot;&quot;,&quot;sizes&quot;:[]},&quot;min_height_mobile&quot;:{&quot;unit&quot;:&quot;px&quot;,&quot;size&quot;:&quot;&quot;,&quot;sizes&quot;:[]}}\" data-widget_type=\"table-of-contents.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<div class=\"elementor-toc__header\">\n\t\t\t\t\t\t<h4 class=\"elementor-toc__header-title\">\n\t\t\t\t\u00cdndice\t\t\t<\/h4>\n\t\t\t\t\t\t\t\t\t\t<div class=\"elementor-toc__toggle-button elementor-toc__toggle-button--expand\" role=\"button\" tabindex=\"0\" aria-controls=\"elementor-toc__071d0c5\" aria-expanded=\"true\" aria-label=\"Open table of 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9.317-33.901-.04l-22.667-22.667c-9.373-9.373-9.373-24.569 0-33.941L207.03 130.525c9.372-9.373 24.568-9.373 33.941-.001z\"><\/path><\/svg><\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<div id=\"elementor-toc__071d0c5\" class=\"elementor-toc__body\">\n\t\t\t<div class=\"elementor-toc__spinner-container\">\n\t\t\t\t<svg class=\"elementor-toc__spinner eicon-animation-spin e-font-icon-svg e-eicon-loading\" aria-hidden=\"true\" viewBox=\"0 0 1000 1000\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M500 975V858C696 858 858 696 858 500S696 142 500 142 142 304 142 500H25C25 237 238 25 500 25S975 237 975 500 763 975 500 975Z\"><\/path><\/svg>\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-8a9139e elementor-invisible elementor-widget elementor-widget-heading\" data-id=\"8a9139e\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;_animation&quot;:&quot;fadeInUp&quot;}\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">O que s\u00e3o materiais termoel\u00e9ctricos?<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-ffaef65 elementor-invisible elementor-widget elementor-widget-text-editor\" data-id=\"ffaef65\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;_animation&quot;:&quot;fadeInUp&quot;}\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>Os materiais termoel\u00e9ctricos podem converter o calor diretamente em energia el\u00e9ctrica. Esta propriedade baseia-se no <a href=\"https:\/\/www.linseis.com\/messgroessen\/seebeck-koeffizient\/\">\n  <strong>efeito Seebeck<\/strong>\n<\/a>em que uma diferen\u00e7a de temperatura aplicada a um material gera uma tens\u00e3o. O inverso \u00e9 o efeito Peltier, que \u00e9 normalmente utilizado para arrefecimento. Um terceiro efeito termoel\u00e9trico \u00e9 o efeito Thomson, que descreve o transporte de calor ao longo de um condutor de corrente no qual existe um gradiente de temperatura.   <\/p><p>Devido \u00e0 possibilidade de utilizar diretamente a energia t\u00e9rmica, os materiais termoel\u00e9ctricos tornaram-se o foco da investiga\u00e7\u00e3o e desenvolvimento. Por um lado, podem ser utilizados <g id=\"gid_1\">para<\/g> <g id=\"gid_0\">gerar<\/g> <g id=\"gid_3\">energia<\/g> <g id=\"gid_2\">el\u00e9ctrica<\/g> <g id=\"gid_5\">a partir de fontes de energia prim\u00e1ria<\/g>; por outro lado, \u00e9 tentador <g id=\"gid_10\">gerar<\/g> <g id=\"gid_8\">eletricidade<\/g> <g id=\"gid_6\">a partir de<\/g> <g id=\"gid_7\">calor residual<\/g>, conservando assim os recursos de combust\u00edveis f\u00f3sseis e, ao mesmo tempo, minimizando o consumo de energia.     <strong>liberta\u00e7\u00e3o<\/strong> <strong>de<\/strong> <strong>CO2<\/strong> <strong>.<\/strong> <\/p><p>Uma vez que a tens\u00e3o el\u00e9ctrica induzida pelo efeito Seebeck \u00e9 muito baixa (normalmente entre algumas e algumas centenas de \u03bcV\/K), est\u00e3o a ser feitos grandes esfor\u00e7os para desenvolver materiais termoel\u00e9ctricos melhorados.<\/p><p>Os materiais termoel\u00e9ctricos cl\u00e1ssicos prov\u00eam do grupo dos semimetais e dos semicondutores (IV a VI grupo principal do PSE) ou s\u00e3o ligas de materiais destes grupos, uma vez que o coeficiente Seebeck \u00e9 particularmente elevado. O efeito Seebeck pode ainda ser aumentado por dopagem. <\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-1295146 elementor-invisible elementor-widget elementor-widget-heading\" data-id=\"1295146\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;_animation&quot;:&quot;fadeInUp&quot;}\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Qual \u00e9 o n\u00famero de qualidade?<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-16fa67b elementor-invisible elementor-widget elementor-widget-text-editor\" data-id=\"16fa67b\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;_animation&quot;:&quot;fadeInUp&quot;}\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>Em geral, um valor de m\u00e9rito \u00e9 uma medida da adequa\u00e7\u00e3o de materiais, m\u00e9todos ou dispositivos em compara\u00e7\u00e3o com alternativas.<\/p><p>O valor de m\u00e9rito termoel\u00e9trico ZT (<a href=\"https:\/\/www.linseis.com\/messgroessen\/zt-figure-of-merit\/\">\n  <strong>figura de m\u00e9rito<\/strong>\n<\/a>&#8220;) descreve a adequa\u00e7\u00e3o dos materiais termoel\u00e9ctricos e \u00e9 definido da seguinte forma:<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-b8b9694 elementor-invisible elementor-widget elementor-widget-heading\" data-id=\"b8b9694\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;_animation&quot;:&quot;fadeInUp&quot;}\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h4 class=\"elementor-heading-title elementor-size-default\">Equa\u00e7\u00e3o 1\n\n<\/h4>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-83c7bca elementor-widget__width-initial elementor-invisible elementor-widget elementor-widget-image\" data-id=\"83c7bca\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;_animation&quot;:&quot;fadeInUp&quot;}\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t<figure class=\"wp-caption\">\n\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"221\" height=\"115\" src=\"https:\/\/www.linseis.com\/wp-content\/uploads\/2024\/07\/ZT-formula-2.png\" class=\"attachment-large size-large wp-image-31940\" alt=\"\" \/>\t\t\t\t\t\t\t\t\t\t\t<figcaption class=\"widget-image-caption wp-caption-text\">com S: coeficiente de Seebeck [\u03bcV\/K] \u03c3: condutividade el\u00e9ctrica [S\/m] \u03bb: condutividade t\u00e9rmica [W\/(m-K)] a uma temperatura T. Todos estes valores dependem da temperatura.<\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-8405690 elementor-invisible elementor-widget elementor-widget-text-editor\" data-id=\"8405690\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;_animation&quot;:&quot;fadeInUp&quot;}\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>Para al\u00e9m do coeficiente de Seebeck mais elevado poss\u00edvel, os materiais termoel\u00e9ctricos devem ter uma baixa <a href=\"https:\/\/www.linseis.com\/messgeraete\/waermeleitfaehigkeit\/\">\n  <strong>condutividade t\u00e9rmica<\/strong>\n<\/a> e uma elevada <a href=\"https:\/\/www.linseis.com\/messgroessen\/elektrische-leitfaehigkeit\/\">\n  <strong>condutividade el\u00e9ctrica<\/strong>\n<\/a> elevada. Os materiais com elevada condutividade t\u00e9rmica n\u00e3o permitem grandes gradientes de temperatura; se a condutividade el\u00e9ctrica for baixa, n\u00e3o \u00e9 poss\u00edvel obter correntes utiliz\u00e1veis. <\/p><p>Al\u00e9m disso, a figura de m\u00e9rito e a diferen\u00e7a de temperatura est\u00e3o diretamente relacionadas com a efici\u00eancia \u03b7 de uma unidade termoel\u00e9ctrica, pelo que esta aumenta quando ZT e \u0394T t\u00eam valores elevados<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-eb81973 elementor-invisible elementor-widget elementor-widget-heading\" data-id=\"eb81973\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;_animation&quot;:&quot;fadeInUp&quot;}\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h4 class=\"elementor-heading-title elementor-size-default\">Equa\u00e7\u00e3o 2\n\n<\/h4>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-8b234ea elementor-widget__width-initial elementor-invisible elementor-widget elementor-widget-image\" data-id=\"8b234ea\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;_animation&quot;:&quot;fadeInUp&quot;}\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"300\" height=\"98\" src=\"https:\/\/www.linseis.com\/wp-content\/uploads\/2024\/07\/Formel-ZT-Gleichung-2-Wirkungsgrad-300x98-1.png\" class=\"attachment-large size-large wp-image-31944\" alt=\"\" \/>\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-4998487 elementor-invisible elementor-widget elementor-widget-heading\" data-id=\"4998487\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;_animation&quot;:&quot;fadeInUp&quot;}\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Otimiza\u00e7\u00e3o de materiais termoel\u00e9ctricos<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-d73544d elementor-invisible elementor-widget elementor-widget-text-editor\" data-id=\"d73544d\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;_animation&quot;:&quot;fadeInUp&quot;}\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>Uma grande variedade de classes de materiais apresenta efeitos termoel\u00e9ctricos de diferentes intensidades. Durante muito tempo, um valor de 1 foi considerado como o valor m\u00e1ximo de m\u00e9rito, mas atualmente alguns materiais optimizados atingem valores de 2 ou superiores. <br><br>Como se pode ver na equa\u00e7\u00e3o 1, h\u00e1 duas abordagens diferentes para aumentar o ZT: ou o chamado fator de pot\u00eancia S2\u03c3 pode ser maximizado e\/ou a condutividade t\u00e9rmica pode ser minimizada. Para o conseguir, os materiais existentes s\u00e3o melhorados, por exemplo, por dopagem, e s\u00e3o desenvolvidos novos materiais. Este \u00faltimo pode ser conseguido atrav\u00e9s da nanoestrutura\u00e7\u00e3o, por exemplo, uma vez que reduz consideravelmente a condutividade t\u00e9rmica sem afetar significativamente o fator de pot\u00eancia. Se a termoeletricidade for utilizada na ind\u00fastria, os custos, a toxicidade e a disponibilidade dos materiais s\u00e3o importantes.   <\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-8cead25 elementor-invisible elementor-widget elementor-widget-heading\" data-id=\"8cead25\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;_animation&quot;:&quot;fadeInUp&quot;}\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Medi\u00e7\u00e3o do valor de m\u00e9rito\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-3ed0642 elementor-invisible elementor-widget elementor-widget-text-editor\" data-id=\"3ed0642\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;_animation&quot;:&quot;fadeInUp&quot;}\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\tExistem v\u00e1rios m\u00e9todos para determinar a figura de m\u00e9rito termoel\u00e9trico.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-3b9f02d elementor-invisible elementor-widget elementor-widget-text-editor\" data-id=\"3b9f02d\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;_animation&quot;:&quot;fadeInUp&quot;}\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<ol><li>Por um lado, os par\u00e2metros individuais (coeficiente de Seebeck, condutividade el\u00e9ctrica e t\u00e9rmica) podem ser medidos e a ZT calculada de acordo com a equa\u00e7\u00e3o 1.<\/li><li>Por outro lado, \u00e9 poss\u00edvel utilizar a ZT diretamente atrav\u00e9s do chamado <a href=\"https:\/\/www.linseis.com\/methoden\/harman-methode\/\">\n  <strong>m\u00e9todo Harman<\/strong>\n<\/a> m\u00e9todo.<\/li><\/ol>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-c0c3b7e elementor-invisible elementor-widget elementor-widget-heading\" data-id=\"c0c3b7e\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;_animation&quot;:&quot;fadeInUp&quot;}\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">1. c\u00e1lculo de acordo com a equa\u00e7\u00e3o 1\n<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-536134f elementor-invisible elementor-widget elementor-widget-text-editor\" data-id=\"536134f\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;_animation&quot;:&quot;fadeInUp&quot;}\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>Existem v\u00e1rios<a href=\"https:\/\/www.linseis.com\/messgeraete\/lsr-thermoelektrik\/lsr-l31\/\">\n  <strong> dispositivos comerciais<\/strong>\n<\/a> est\u00e3o dispon\u00edveis para a medi\u00e7\u00e3o quase simult\u00e2nea da condutividade el\u00e9ctrica e do coeficiente de Seebeck. A condutividade t\u00e9rmica ou difusividade t\u00e9rmica \u00e9 normalmente determinada utilizando o m\u00e9todo do laser ou do flash de luz. O resultado direto deste m\u00e9todo \u00e9 a difusividade t\u00e9rmica. Se a densidade e a condutividade t\u00e9rmica espec\u00edfica forem conhecidas.   <\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-5c329c6 elementor-widget elementor-widget-spacer\" data-id=\"5c329c6\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"spacer.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<div class=\"elementor-spacer\">\n\t\t\t<div class=\"elementor-spacer-inner\"><\/div>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-2d6449d elementor-invisible elementor-widget elementor-widget-text-editor\" data-id=\"2d6449d\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;_animation&quot;:&quot;fadeInUp&quot;}\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>A condutividade t\u00e9rmica pode ser calculada a partir da seguinte f\u00f3rmula?<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-8709dbd elementor-widget__width-initial elementor-invisible elementor-widget elementor-widget-image\" data-id=\"8709dbd\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;_animation&quot;:&quot;fadeInUp&quot;}\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t<figure class=\"wp-caption\">\n\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"340\" height=\"127\" src=\"https:\/\/www.linseis.com\/wp-content\/uploads\/2024\/07\/Formel-Warmeleitfahigkeit.png\" class=\"attachment-large size-large wp-image-31948\" alt=\"\" srcset=\"https:\/\/www.linseis.com\/wp-content\/uploads\/2024\/07\/Formel-Warmeleitfahigkeit.png 340w, https:\/\/www.linseis.com\/wp-content\/uploads\/2024\/07\/Formel-Warmeleitfahigkeit-300x112.png 300w\" sizes=\"(max-width: 340px) 100vw, 340px\" \/>\t\t\t\t\t\t\t\t\t\t\t<figcaption class=\"widget-image-caption wp-caption-text\">com: \u03bb: Condutividade t\u00e9rmica [W\/(m-K)] a: Difusividade t\u00e9rmica [m\u00b2\/s] r: Densidade [g\/m3] Cp: Capacidade t\u00e9rmica espec\u00edfica [J\/(g\/K)]<\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-28f2c3f elementor-invisible elementor-widget elementor-widget-text-editor\" data-id=\"28f2c3f\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;_animation&quot;:&quot;fadeInUp&quot;}\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>Todas estas vari\u00e1veis dependem da temperatura.<br><br><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-3ad86f1 elementor-invisible elementor-widget elementor-widget-text-editor\" data-id=\"3ad86f1\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;_animation&quot;:&quot;fadeInUp&quot;}\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\tIsto significa que um total de cinco vari\u00e1veis (dependentes da temperatura) devem ser determinadas para calcular a figura de m\u00e9rito. Uma an\u00e1lise de erro pode ser encontrada na literatura [1]. \t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-7f0150a elementor-invisible elementor-widget elementor-widget-heading\" data-id=\"7f0150a\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;_animation&quot;:&quot;fadeInUp&quot;}\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">2. determina\u00e7\u00e3o pelo m\u00e9todo de Harman\n<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-fb3a7a6 elementor-invisible elementor-widget elementor-widget-text-editor\" data-id=\"fb3a7a6\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;_animation&quot;:&quot;fadeInUp&quot;}\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\tO chamado m\u00e9todo Harman permite a medi\u00e7\u00e3o direta da figura de m\u00e9rito. Para o efeito, faz-se passar uma pequena corrente atrav\u00e9s de uma amostra em forma de barra em condi\u00e7\u00f5es adiab\u00e1ticas. A queda de tens\u00e3o observada \u00e9 composta por um componente \u00f3hmico (UR; resist\u00eancia el\u00e9ctrica) e um componente termoel\u00e9trico causado pelo efeito Seebeck (Uth; tens\u00e3o termoel\u00e9ctrica). Ao contr\u00e1rio da componente \u00f3hmica, que ocorre espontaneamente, a componente causada pelo efeito Seebeck acumula-se lentamente:   \t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-7cccb95 elementor-invisible elementor-widget elementor-widget-image\" data-id=\"7cccb95\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;_animation&quot;:&quot;fadeInUp&quot;}\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t<figure class=\"wp-caption\">\n\t\t\t\t\t\t\t\t\t\t<img loading=\"lazy\" decoding=\"async\" width=\"800\" height=\"439\" src=\"https:\/\/www.linseis.com\/wp-content\/uploads\/2024\/07\/LSR-Harman-1024x562.png\" class=\"attachment-large size-large wp-image-33720\" alt=\"\" srcset=\"https:\/\/www.linseis.com\/wp-content\/uploads\/2024\/07\/LSR-Harman-1024x562.png 1024w, https:\/\/www.linseis.com\/wp-content\/uploads\/2024\/07\/LSR-Harman-300x165.png 300w, https:\/\/www.linseis.com\/wp-content\/uploads\/2024\/07\/LSR-Harman-768x422.png 768w, https:\/\/www.linseis.com\/wp-content\/uploads\/2024\/07\/LSR-Harman-1536x843.png 1536w, https:\/\/www.linseis.com\/wp-content\/uploads\/2024\/07\/LSR-Harman-2048x1124.png 2048w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/>\t\t\t\t\t\t\t\t\t\t\t<figcaption class=\"widget-image-caption wp-caption-text\">Medi\u00e7\u00e3o de ZT com o m\u00e9todo Harman<\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-12f9d93 elementor-invisible elementor-widget elementor-widget-text-editor\" data-id=\"12f9d93\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;_animation&quot;:&quot;fadeInUp&quot;}\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\tO n\u00famero de qualidade obt\u00e9m-se dividindo as duas propor\u00e7\u00f5es:\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-7ff4a03 elementor-invisible elementor-widget elementor-widget-heading\" data-id=\"7ff4a03\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;_animation&quot;:&quot;fadeInUp&quot;}\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h4 class=\"elementor-heading-title elementor-size-default\">Equa\u00e7\u00e3o 4\n\n<\/h4>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-4cd93bb elementor-widget__width-initial elementor-invisible elementor-widget elementor-widget-image\" data-id=\"4cd93bb\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;_animation&quot;:&quot;fadeInUp&quot;}\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t<figure class=\"wp-caption\">\n\t\t\t\t\t\t\t\t\t\t<img loading=\"lazy\" decoding=\"async\" width=\"171\" height=\"127\" src=\"https:\/\/www.linseis.com\/wp-content\/uploads\/2024\/07\/ZT-formula.png\" class=\"attachment-large size-large wp-image-31961\" alt=\"\" \/>\t\t\t\t\t\t\t\t\t\t\t<figcaption class=\"widget-image-caption wp-caption-text\">com: Uth: componente termoel\u00e9ctrica (Seebeck) da queda de tens\u00e3o UR: componente \u00f3hmica (resistiva) da queda de tens\u00e3o<\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-51281f4 elementor-invisible elementor-widget elementor-widget-heading\" data-id=\"51281f4\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;_animation&quot;:&quot;fadeInUp&quot;}\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h4 class=\"elementor-heading-title elementor-size-default\">Literatura:\n\n<\/h4>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-35f5662 elementor-invisible elementor-widget elementor-widget-text-editor\" data-id=\"35f5662\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;_animation&quot;:&quot;fadeInUp&quot;}\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>[1] A. Alleno et al, A round robin test of the uncertainty on the measurement.of the thermoelectric dimensionless figure of merit of Co0.97Ni0.03Sb3, REVIEW OF SCIENTIFIC INSTRUMENTS 86, 011301 (2015).<br><br>[2] T.C. Harman, Journal of Applied Physics 29, 1373 (1958).<br><br>[3] T. C. Harman, J. H. Cahn, e M. J. Logan, J. Appl. Phys.  30(9), 1351 (1959).<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-87d5950 elementor-widget elementor-widget-spacer\" data-id=\"87d5950\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"spacer.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<div class=\"elementor-spacer\">\n\t\t\t<div class=\"elementor-spacer-inner\"><\/div>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"<p>Os materiais termoel\u00e9ctricos podem converter calor diretamente em energia el\u00e9ctrica. Esta propriedade baseia-se no efeito Seebeck, em que uma diferen\u00e7a de temperatura aplicada a um material gera uma tens\u00e3o. <\/p>\n","protected":false},"author":3,"featured_media":31936,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":""},"categories":[654],"tags":[],"class_list":["post-103298","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-conhecimentos"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.linseis.com\/pt-pt\/wp-json\/wp\/v2\/posts\/103298","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.linseis.com\/pt-pt\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.linseis.com\/pt-pt\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.linseis.com\/pt-pt\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.linseis.com\/pt-pt\/wp-json\/wp\/v2\/comments?post=103298"}],"version-history":[{"count":0,"href":"https:\/\/www.linseis.com\/pt-pt\/wp-json\/wp\/v2\/posts\/103298\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.linseis.com\/pt-pt\/wp-json\/wp\/v2\/media\/31936"}],"wp:attachment":[{"href":"https:\/\/www.linseis.com\/pt-pt\/wp-json\/wp\/v2\/media?parent=103298"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.linseis.com\/pt-pt\/wp-json\/wp\/v2\/categories?post=103298"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.linseis.com\/pt-pt\/wp-json\/wp\/v2\/tags?post=103298"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}