Karbid k\u0159em\u00edku neboli SiC je extr\u00e9mn\u011b pevn\u00fd a odoln\u00fd materi\u00e1l s n\u011bkter\u00fdmi jedine\u010dn\u00fdmi elektrick\u00fdmi vlastnostmi.<\/p>\n
Krystalick\u00fd uhl\u00edk krystalizuje do hust\u011b uspo\u0159\u00e1dan\u00fdch struktur, kter\u00e9 jsou kovalentn\u011b v\u00e1z\u00e1ny. Jeho atomy tvo\u0159\u00ed dva prim\u00e1rn\u00ed koordina\u010dn\u00ed tetraedry se \u010dty\u0159mi atomy uhl\u00edku a \u010dty\u0159mi atomy k\u0159em\u00edku v ka\u017ed\u00e9m rohu, kter\u00e9 se propojuj\u00ed p\u0159es sv\u00e9 rohy a vytv\u00e1\u0159ej\u00ed polytypov\u00e9 struktury zvan\u00e9 polytypy.<\/p>\n
Karbid k\u0159em\u00edku je extr\u00e9mn\u011b tvrd\u00fd materi\u00e1l s tvrdost\u00ed podle Mohsovy stupnice mezi 9 a 10, tedy n\u011bkde mezi oxidem hlinit\u00fdm a diamantem. Karbid k\u0159em\u00edku nach\u00e1z\u00ed \u0161irok\u00e9 uplatn\u011bn\u00ed jako abrazivn\u00ed materi\u00e1l v modern\u00edm lapid\u00e1riu, p\u0159i brou\u0161en\u00ed a obr\u00e1b\u011bn\u00ed, jako \u017e\u00e1ruvzdorn\u00e1 vyzd\u00edvka pr\u016fmyslov\u00fdch pec\u00ed, \u0159ezn\u00e9 n\u00e1stroje, ot\u011bruvzdorn\u00e9 sou\u010d\u00e1sti \u010derpadel a raketov\u00fdch motor\u016f a tak\u00e9 jako ot\u011bruvzdorn\u00e1 \u00fachopov\u00e1 p\u00e1ska na skateboardech a tak\u00e9 v karborundov\u00e9 grafice - procesu nan\u00e1\u0161en\u00ed karborundov\u00e9 drti na hlin\u00edkovou desku a n\u00e1sledn\u00e9ho tisku na pap\u00edr pomoc\u00ed v\u00e1lcovac\u00edch lis\u016f (Mountain).<\/p>\n
Syntetick\u00e9 polykarbon\u00e1ty lze vyr\u00e1b\u011bt synteticky bu\u010f reak\u010dn\u00ed vazbou, nebo sp\u00e9k\u00e1n\u00edm, p\u0159i\u010dem\u017e sp\u00e9k\u00e1n\u00ed je vylep\u0161eno p\u0159id\u00e1n\u00edm 0,5% uhl\u00edku nebo 0,5% b\u00f3ru jako pomocn\u00e9 l\u00e1tky p\u0159i sp\u00e9k\u00e1n\u00ed, aby se zabr\u00e1nilo povrchov\u00e9 dif\u00fazi a zm\u011bnila se energie na hranici zrn (Mountain).<\/p>\n
SiC je p\u016fsobiv\u00e1 pr\u016fmyslov\u00e1 keramika s rozmanit\u00fdmi mechanick\u00fdmi vlastnostmi, kter\u00e9 ji \u010din\u00ed neocenitelnou v r\u016fzn\u00fdch pr\u016fmyslov\u00fdch prost\u0159ed\u00edch. D\u00edky vysok\u00e9 tepeln\u00e9 vodivosti a n\u00edzk\u00e9 tepeln\u00e9 rozta\u017enosti se jeho pou\u017eit\u00ed ve v\u00fdkonov\u00e9 elektronice pro pohonn\u00e9 syst\u00e9my pozemn\u00edch elektrick\u00fdch vozidel roz\u0161\u00ed\u0159ilo v\u00edce ne\u017e kdy jindy. Elektrick\u00e9 vlastnosti SiC by nav\u00edc mohly nahradit tradi\u010dn\u00ed k\u0159em\u00edkov\u00e9 polovodi\u010de i v aplikac\u00edch s vy\u0161\u0161\u00edm nap\u011bt\u00edm, jako jsou trak\u010dn\u00ed m\u011bni\u010de pro elektromobily a DC\/DC m\u011bni\u010de pro nab\u00edjec\u00ed stanice.<\/p>\n
Karbid k\u0159em\u00edku lze dopovat dus\u00edkem a fosforem, \u010d\u00edm\u017e vznikaj\u00ed polovodi\u010de typu n, zat\u00edmco beryliem, b\u00f3rem, hlin\u00edkem a heliem lze dopovat polovodi\u010de typu p. Karbid k\u0159em\u00edku je d\u00edky sv\u00e9 t\u011bsn\u00e9 a symetrick\u00e9 struktu\u0159e ide\u00e1ln\u00ed platformou pro dopov\u00e1n\u00ed.<\/p>\n
\u017d\u00e1ruvzdorn\u00fd materi\u00e1l je tvrd\u00fd, k\u0159ehk\u00fd a tepeln\u011b vodiv\u00fd. Odol\u00e1v\u00e1 vysok\u00fdm teplot\u00e1m a nap\u011bt\u00edm a jeho n\u00edzk\u00fd koeficient tepeln\u00e9 rozta\u017enosti je v\u00fdhodou p\u0159i pou\u017eit\u00ed v aplikac\u00edch, kde doch\u00e1z\u00ed ke zm\u011bn\u00e1m teplot.<\/p>\n
A\u010dkoli se p\u0159\u00edrodn\u00ed moissanit (Csi3SiO6) nach\u00e1z\u00ed v meteoritech a kimberlitu, v\u011bt\u0161ina dnes prod\u00e1van\u00e9ho karbidu k\u0159em\u00edku je syntetick\u00e1. Vyr\u00e1b\u00ed se v mnoha form\u00e1ch, od zelen\u00fdch a\u017e po \u010dern\u00e1 krystalick\u00e1 zrna a \u0161estipalcov\u00e9 desti\u010dky SiC pou\u017e\u00edvan\u00e9 pro aplikace ve v\u00fdkonov\u00e9 elektronice, a je chemicky inertn\u00ed, proto\u017ee odol\u00e1v\u00e1 korozi organick\u00fdmi kyselinami a z\u00e1sadami, s v\u00fdjimkou kyseliny fluorovod\u00edkov\u00e9 a s\u00edrov\u00e9; je nerozpustn\u00fd ve vod\u011b nebo jin\u00fdch rozpou\u0161t\u011bdlech, ale rozpustn\u00fd v roztaven\u00fdch z\u00e1sad\u00e1ch, jako je NaOH nebo KOH.<\/p>\n
Karbid k\u0159em\u00edku (SiC) je polovodi\u010dov\u00fd materi\u00e1l, kter\u00fd se nach\u00e1z\u00ed mezi kovy (kter\u00e9 vedou elektrick\u00fd proud) a izolanty (kter\u00e9 elektrick\u00fd proud nevedou). Elektrick\u00e9 vlastnosti SiC z\u00e1vis\u00ed na teplot\u011b a p\u0159\u00edm\u011bs\u00edch v jeho slo\u017een\u00ed: p\u0159i n\u00edzk\u00fdch teplot\u00e1ch se chov\u00e1 jako izolant, zat\u00edmco p\u0159i vy\u0161\u0161\u00edch teplot\u00e1ch je jeho vodivost znateln\u00e1. Vodivost SiC lze d\u00e1le zlep\u0161it p\u0159id\u00e1n\u00edm p\u0159\u00edm\u011bs\u00ed hlin\u00edku, b\u00f3ru nebo galia, kter\u00e9 zvy\u0161uj\u00ed mno\u017estv\u00ed voln\u00fdch nosi\u010d\u016f n\u00e1boje a p\u0159em\u011b\u0148uj\u00ed SiC na polovodi\u010d typu P.<\/p>\n
Kombinace fyzik\u00e1ln\u00edch a chemick\u00fdch vlastnost\u00ed j\u00edlu z n\u011bj \u010din\u00ed atraktivn\u00ed materi\u00e1l v r\u016fzn\u00fdch pr\u016fmyslov\u00fdch odv\u011btv\u00edch, od keramick\u00fdch desek, kter\u00e9 zvy\u0161uj\u00ed odolnost proti ot\u011bru a pevnost brzd, a\u017e po vysokou tepelnou vodivost a n\u00edzk\u00fd koeficient rozta\u017enosti, kter\u00e9 umo\u017e\u0148uj\u00ed jeho pou\u017eit\u00ed v aplikac\u00edch s vysok\u00fdmi teplotami.<\/p>\n
Nav\u00edc jeho jedine\u010dn\u00e1 p\u00e1smov\u00e1 propust umo\u017e\u0148uje pracovat p\u0159i vy\u0161\u0161\u00edch nap\u011bt\u00edch a frekvenc\u00edch ne\u017e tradi\u010dn\u00ed elektronika na b\u00e1zi k\u0159em\u00edku, co\u017e z n\u011bj \u010din\u00ed ide\u00e1ln\u00ed materi\u00e1l pro v\u00fdkonov\u00e1 za\u0159\u00edzen\u00ed, jako jsou diody, tranzistory a tyristory.<\/p>\n
Karbid k\u0159em\u00edku (SiC) je anorganick\u00e1 keramika s vynikaj\u00edc\u00edmi tepeln\u00fdmi vlastnostmi, kter\u00e1 je vhodn\u00e1 pro mnoho r\u016fzn\u00fdch aplikac\u00ed. Karbid k\u0159em\u00edku nach\u00e1z\u00ed uplatn\u011bn\u00ed v r\u016fzn\u00fdch aplikac\u00edch, od d\u00edl\u016f odoln\u00fdch proti opot\u0159eben\u00ed a abraziv d\u00edky sv\u00e9 tvrdosti; v \u017e\u00e1ruvzdorn\u00fdch materi\u00e1lech a keramice d\u00edky sv\u00e9 odolnosti v\u016f\u010di teplu a n\u00edzk\u00e9 tepeln\u00e9 rozta\u017enosti; a tak\u00e9 v elektronice, kde jeho schopnost v\u00e9st elektrick\u00fd proud p\u0159i extr\u00e9mn\u00edch teplot\u00e1ch.<\/p>\n
SiC je \u00fa\u010dinn\u00fdm tepeln\u00fdm vodi\u010dem d\u00edky sv\u00e9 krystalov\u00e9 struktu\u0159e diamantov\u00e9 kostky, v n\u00ed\u017e je polovina atom\u016f nahrazena k\u0159em\u00edkem, co\u017e zaji\u0161\u0165uje vynikaj\u00edc\u00ed tepelnou vodivost. SiC m\u00e1 \u00fa\u010dinnou p\u00e1smovou mezeru, kter\u00e1 umo\u017e\u0148uje elektron\u016fm snadno p\u0159ech\u00e1zet mezi jeho valen\u010dn\u00edmi a vodivostn\u00edmi p\u00e1sy ve srovn\u00e1n\u00ed s izolanty, kter\u00e9 vy\u017eaduj\u00ed nadm\u011brn\u00e9 mno\u017estv\u00ed energie, aby elektrony mohly tuto mezeru mezi p\u00e1sy p\u0159ekonat.<\/p>\n
Krystalov\u00e1 struktura SiC m\u016f\u017ee nab\u00fdvat r\u016fzn\u00fdch forem, tzv. polytyp\u016f. Ka\u017ed\u00fd polytyp se skl\u00e1d\u00e1 z vrstev poskl\u00e1dan\u00fdch ve specifick\u00e9m uspo\u0159\u00e1d\u00e1n\u00ed, kter\u00e9 vede k jedine\u010dn\u00e9mu uspo\u0159\u00e1d\u00e1n\u00ed atom\u016f - d\u00edky tomu m\u00e1 SiC extr\u00e9mn\u011b vysok\u00e9 m\u011brn\u00e9 teplo a n\u00edzk\u00fd koeficient tepeln\u00e9 rozta\u017enosti.<\/p>","protected":false},"excerpt":{"rendered":"
Silicon carbide, or SiC, is an extremely strong and durable material with some unique electrical properties. Crystalline carbon can be […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""}},"footnotes":""},"categories":[3],"tags":[],"class_list":["post-42","post","type-post","status-publish","format-standard","hentry","category-sic-knowledge"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/posts\/42","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/comments?post=42"}],"version-history":[{"count":1,"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/posts\/42\/revisions"}],"predecessor-version":[{"id":43,"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/posts\/42\/revisions\/43"}],"wp:attachment":[{"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/media?parent=42"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/categories?post=42"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/tags?post=42"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}