Sil\u012bcija karb\u012bds (SiC) ir \u012bpa\u0161i ciets sint\u0113tisks materi\u0101ls, ko 1891. gad\u0101 pirmo reizi sintez\u0113ja Edvards A\u010dons kr\u0101sn\u012b, kars\u0113jot oglekli un alum\u012bnija oks\u012bdu. Kop\u0161 20. gadsimta 20. gados SiC s\u0101ka izmantot r\u016bpniec\u012bb\u0101 k\u0101 r\u016bpniecisku abraz\u012bvu, tas \u0101tri k\u013cuva par vienu no vispiepras\u012bt\u0101kajiem materi\u0101liem pla\u0161\u0101 m\u0113rog\u0101.<\/p>\n
SiC ir da\u017e\u0101du krist\u0101lisko strukt\u016bru, kas paz\u012bstamas k\u0101 politipi; lieljaudas lietojumiem vislab\u0101k piem\u0113rots 4H-SiC heksagon\u0101l\u0101s atom\u0101r\u0101s strukt\u016bras politips.<\/p>\n
Sil\u012bcija karb\u012bds ir smalka keramika ar daudzveid\u012bg\u0101m fizik\u0101laj\u0101m \u012bpa\u0161\u012bb\u0101m, kas to padara par vienu no visdaudzpus\u012bg\u0101kajiem ugunsiztur\u012bgajiem materi\u0101liem tirg\u016b. No t\u0101 iztur\u012bbas, ciet\u012bbas, iztur\u012bbas pret koroziju un augst\u0101 ku\u0161anas punkta l\u012bdz t\u0101 daudzpus\u012bgumam ekstr\u0113mos in\u017eeniertehniskajos lietojumos, piem\u0113ram, s\u016bk\u0146u gult\u0146os, v\u0101rstos, smil\u0161u str\u016bklas in\u017eektoros un ekstr\u016bzijas presform\u0101s, sil\u012bcija karb\u012bds ir pier\u0101d\u012bjis sevi k\u0101 b\u016btisku m\u016bsdienu elektronisko ier\u012b\u010du elementu. Papildus \u0161\u012bm iespaid\u012bgaj\u0101m meh\u0101niskaj\u0101m \u012bpa\u0161\u012bb\u0101m sil\u012bcija karb\u012bds k\u0101 neaizst\u0101jama sast\u0101vda\u013ca pied\u0101v\u0101 ar\u012b noz\u012bm\u012bgas pusvad\u012bt\u0101ju \u012bpa\u0161\u012bbas.<\/p>\n
T\u012brs sil\u012bcija karb\u012bds ir bezkr\u0101saina krist\u0101liska viela, kuras bl\u012bvums ir 3,21 g\/ml un ku\u0161anas temperat\u016bra p\u0101rsniedz 2700 gr\u0101dus p\u0113c Celsija. Bie\u017ei tiek ra\u017eots A\u010desona proces\u0101, kur sil\u012bcija smiltis un koksu apvieno un kars\u0113 augst\u0101 temperat\u016br\u0101 elektriskaj\u0101 kr\u0101sn\u012b, l\u012bdz sil\u012bcija smiltis karboniz\u0113jas, veidojot rupjkrist\u0101liskas strukt\u016bras, piem\u0113ram, a-SiC, bet b-SiC liet\u0146os veidojas dimanta kubiskas strukt\u016bras.<\/p>\n
Alfa-SiC ir visbie\u017e\u0101k sastopamais sil\u012bcija karb\u012bda polimorfs, kam rakstur\u012bga se\u0161st\u016braina krist\u0101lisk\u0101 strukt\u016bra, l\u012bdz\u012bga virtc\u012btam. Beta-SiC formas ar dimanta kubisku krist\u0101lisko strukt\u016bru visbie\u017e\u0101k sastopamas meteor\u012btos; turkl\u0101t \u0161\u012b forma bie\u017ei tiek izmantota r\u016bpnieciskaj\u0101 ra\u017eo\u0161an\u0101, kaus\u0113jot un lejot da\u017e\u0101dus izstr\u0101d\u0101jumus.<\/p>\n
Sil\u012bcija karb\u012bds ir iztur\u012bga bezoks\u012bda keramika ar iev\u0113rojam\u0101m fizik\u0101l\u0101m un \u0137\u012bmisk\u0101m \u012bpa\u0161\u012bb\u0101m: augstu ciet\u012bbu un stingr\u012bbu, zemu termisk\u0101s izple\u0161an\u0101s \u0101trumu un izcilu iztur\u012bbu pret koroziju. Turkl\u0101t t\u0101 pla\u0161\u0101 joslas sprauga padara to piem\u0113rotu lielas jaudas elektronikas lietojumiem.<\/p>\n
\u016adens, alkohols un liel\u0101k\u0101 da\u013ca sk\u0101bju, iz\u0146emot fluor\u016bde\u0146ra\u017esk\u0101bi un sk\u0101bos fluor\u012bdus, to ne\u0161\u0137\u012bdina, nodro\u0161inot augst\u0101ku \u0137\u012bmisko stabilit\u0101ti sal\u012bdzin\u0101jum\u0101 ar liel\u0101ko da\u013cu citas ugunsiztur\u012bg\u0101s keramikas.<\/p>\n
Sil\u012bcija karb\u012bdu pirmo reizi m\u0101ksl\u012bgi sintez\u0113ja Edvards A\u010dons 1891. gad\u0101 k\u0101 nejau\u0161u blakusproduktu elektriski kars\u0113tam oglek\u013ca un alum\u012bnija oks\u012bda kaus\u0113jumam, un tas ir k\u013cuvis par vienu no pasaul\u0113 svar\u012bg\u0101kaj\u0101m r\u016bpnieciskaj\u0101m keramik\u0101m, ko izmanto gan k\u0101 abraz\u012bvu materi\u0101lu t\u0113rauda sakaus\u0113jumiem, gan k\u0101 struktur\u0101lo keramiku.<\/p>\n
Sil\u012bcija karb\u012bdam piem\u012bt cie\u0161i sak\u0101rtots tetraedru izk\u0101rtojums, kas ir kovalenti savienots kop\u0101. Da\u017e\u0101das sak\u0101rtojuma sec\u012bbas veido da\u017e\u0101dus politipus, no kuriem katrs at\u0161\u0137iras ar at\u0161\u0137ir\u012bg\u0101m fizik\u0101l\u0101m un \u0137\u012bmisk\u0101m \u012bpa\u0161\u012bb\u0101m.<\/p>\n
Alfa formai (a-SiC) ir heksagon\u0101la krist\u0101lisk\u0101 strukt\u016bra, kas l\u012bdz\u012bga virtc\u012btam, bet t\u0101s beta versijai (b-SiC) ir cinka blende krist\u0101lisk\u0101 strukt\u016bra, kas l\u012bdz\u012bga dimantam. Abas SiC \u0161\u0137irnes var viegli apstr\u0101d\u0101t ar ierobe\u017eotiem ciet\u012bbas ierobe\u017eojumiem, un t\u0101s var sl\u012bp\u0113t da\u017e\u0101d\u0101s form\u0101s, lai izmantotu k\u0101 abraz\u012bvus izstr\u0101d\u0101jumus vai teleskopu spogu\u013cus, kas ir popul\u0101ri \u0161o materi\u0101lu lietojumi.<\/p>\n
Sil\u012bcija karb\u012bds ir pusvad\u012bt\u0101ju materi\u0101ls, kas noz\u012bm\u0113, ka tam piem\u012bt da\u017eas \u012bpa\u0161\u012bbas, kuras piem\u012bt gan met\u0101liem (kas vada elektr\u012bbu), gan nemet\u0101liem, piem\u0113ram, izolatoriem (kas ir pret elektr\u012bbas pl\u016bsmu). Prec\u012bzs t\u0101 elektrisko \u012bpa\u0161\u012bbu raksturs ir atkar\u012bgs no temperat\u016bras un krist\u0101liskaj\u0101 strukt\u016br\u0101 eso\u0161ajiem piemais\u012bjumiem - zem\u0101k\u0101s temperat\u016br\u0101s tas darbojas vair\u0101k k\u0101 izolators, kas pretojas elektr\u012bbas pl\u016bsmai, bet augst\u0101k\u0101 temperat\u016br\u0101 tas k\u013c\u016bst vair\u0101k l\u012bdz\u012bgs vad\u012bt\u0101jam un \u013cauj elektr\u012bbai caur to pl\u016bst.<\/p>\n
SiC krist\u0101lisko strukt\u016bru veido sl\u0101\u0146i, ko veido sil\u012bcija un oglek\u013ca atomi, kas saist\u012bti tetraedr\u0101l\u0101s konfigur\u0101cij\u0101s. \u0160ie cie\u0161i sak\u0101rtoti sl\u0101\u0146i veido bl\u012bvi sak\u0101rtotu strukt\u016bru, kas rada da\u017e\u0101das krist\u0101lisk\u0101s strukt\u016bras, ko sauc par politipiem; katram politipam ir vien\u0101ds \u0137\u012bmiskais sast\u0101vs, bet at\u0161\u0137ir\u012bga krist\u0101lisk\u0101 strukt\u016bra, kas ietekm\u0113 t\u0101 elektrisk\u0101s \u012bpa\u0161\u012bbas. Katra politipa sl\u0101\u0146u sak\u0101rto\u0161anas sec\u012bba var veidot kubisku, heksagon\u0101lu vai rombveida krist\u0101lisko strukt\u016bru.<\/p>\n
SiC ir pievilc\u012bgs materi\u0101ls augstsprieguma ener\u0123ijas ier\u012bc\u0113m, jo t\u0101 tetraedrisk\u0101 krist\u0101lisk\u0101 strukt\u016bra un pla\u0161\u0101 elektronisk\u0101s joslas sprauga padara to \u012bpa\u0161i piem\u0113rotu diod\u0113m un tranzistoriem. SiC pla\u0161\u0101k\u0101 elektronisk\u0101 joslu atstarpe \u013cauj tam iztur\u0113t liel\u0101kus elektriskos lauka p\u0101rr\u0101vumus nek\u0101 sil\u012bcijam, vienlaikus samazinot komut\u0101cijas zudumus, kas pal\u012bdz uzlabot energoefektivit\u0101ti. Turkl\u0101t porain\u0101 sil\u012bcija karb\u012bda elektrovad\u012btsp\u0113ju var modific\u0113t, to dop\u0113jot ar piemais\u012bjumiem, lai pan\u0101ktu gan augst\u0101ku elektrovad\u012btsp\u0113ju, gan sprieguma sp\u0113ju, ko var izmantot efekt\u012bvos jaudas p\u0101rveidot\u0101jos, kas paredz\u0113ti elektromobi\u013cu ener\u0123ijas p\u0101rveidot\u0101jiem.<\/p>\n
Sil\u012bcija karb\u012bds ir \u0101rk\u0101rt\u012bgi ciets, \u0137\u012bmiski inerts materi\u0101ls, kas dab\u0101 sastopams k\u0101 melnie dimanti ar Mosa ciet\u012bbas pak\u0101pi 9. Tam piem\u012bt daudzas izdev\u012bgas \u012bpa\u0161\u012bbas, tostarp temperat\u016bras stabilit\u0101te, zems termisk\u0101s izple\u0161an\u0101s \u0101trums un iztur\u012bba pret \u0137\u012bmisko iedarb\u012bbu, t\u0101p\u0113c tas ir ide\u0101li piem\u0113rots k\u0101 pusvad\u012bt\u0101ju materi\u0101ls.<\/p>\n
Litija oks\u012bds ir izcils elektriskais izolators ar desmit reizes augst\u0101ku sprieguma pretest\u012bbas koeficientu nek\u0101 sil\u012bcijs, t\u0101p\u0113c tas k\u013c\u016bst arvien pievilc\u012bg\u0101ks k\u0101 sil\u012bcija aizst\u0101j\u0113jmateri\u0101ls energoelektronik\u0101 un citos jaud\u012bgos lietojumos.<\/p>\n
SiC tiek veidots, izmantojot da\u017e\u0101das polimorfas krist\u0101lisk\u0101s strukt\u016bras, kur\u0101m katrai ir savs \u012bpa\u0161s atomu izk\u0101rtojums. Tr\u012bs visbie\u017e\u0101k ra\u017eotie SiC politipi ir 3C-SiC, 4H-SiC un 6H-SiC; tie at\u0161\u0137iras ar sl\u0101\u0146u sak\u0101rto\u0161anas sec\u012bbu, kas rada at\u0161\u0137ir\u012bgas fizik\u0101l\u0101s un meh\u0101nisk\u0101s \u012bpa\u0161\u012bbas.<\/p>\n
Nesen veiktie p\u0113t\u012bjumi par atsevi\u0161\u0137iem SiC nanopavedieniem ar da\u017e\u0101diem ODD struktur\u0101l\u0101s aiz\u0146emt\u012bbas koeficientiem tika test\u0113ti stiepes testos in-situ ar SEM, lai nov\u0113rt\u0113tu to stipr\u012bbu un elast\u012bbu, b\u012bdes moduli, katras f\u0101zes Puasona koeficienta apr\u0113\u0137inus, meh\u0101nisk\u0101s anizotropijas anal\u012bzi, atkl\u0101ja, ka Pm-SiC ir sp\u0113c\u012bg\u0101kas b\u012bdes \u012bpa\u0161\u012bbas sal\u012bdzin\u0101jum\u0101 ar b-SiC un Pnnm-SiC NWs; turkl\u0101t stipr\u012bba palielin\u0101j\u0101s, pieaugot ODD aiz\u0146emt\u012bbas koeficientam, l\u012bdz tika sasniegts 32,6%, p\u0113c tam stipr\u012bba s\u0101ka eksponenci\u0101li samazin\u0101ties.<\/p>","protected":false},"excerpt":{"rendered":"
Silicon carbide (SiC) is an ultrahard synthetic material first synthesized in 1891 by Edward Acheson in a furnace heated with carbon and alumina. Since its release into industry as an industrial abrasive in the 1920s, SiC has quickly become one of the most sought-after materials on a large scale. SiC comes in various crystal structures […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","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":[64],"tags":[],"class_list":["post-335","post","type-post","status-publish","format-standard","hentry","category-knowledge"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/ceramicatijolart.com\/lv\/wp-json\/wp\/v2\/posts\/335","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ceramicatijolart.com\/lv\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ceramicatijolart.com\/lv\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ceramicatijolart.com\/lv\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ceramicatijolart.com\/lv\/wp-json\/wp\/v2\/comments?post=335"}],"version-history":[{"count":1,"href":"https:\/\/ceramicatijolart.com\/lv\/wp-json\/wp\/v2\/posts\/335\/revisions"}],"predecessor-version":[{"id":336,"href":"https:\/\/ceramicatijolart.com\/lv\/wp-json\/wp\/v2\/posts\/335\/revisions\/336"}],"wp:attachment":[{"href":"https:\/\/ceramicatijolart.com\/lv\/wp-json\/wp\/v2\/media?parent=335"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ceramicatijolart.com\/lv\/wp-json\/wp\/v2\/categories?post=335"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ceramicatijolart.com\/lv\/wp-json\/wp\/v2\/tags?post=335"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}