Inkqubo esisiseko yeSiCukukhula kwekristale kwahlulwe kwi-sublimation kunye nokubola kwezinto eziluhlaza kwiqondo lokushisa eliphezulu, ukuthuthwa kwezinto zesigaba segesi phantsi kwesenzo se-gradient yeqondo lokushisa, kunye nokukhula ngokutsha kwezinto zesigaba segesi kwikristale yembewu. Ngokusekelwe kule nto, ingaphakathi le-crucible lihlukaniswe libe ngamacandelo amathathu: indawo ekrwada, igumbi lokukhula kunye nekristale yembewu. Imodeli yokulinganisa amanani yazotywa ngokusekwe kweyona nto ixhathisayoSiCizixhobo zokukhula kwekristale enye (jonga uMfanekiso 1). Ekubaleni: ezantsi kwei-crucibleI-90 mm kude nezantsi kwe-heater esecaleni, ubushushu obuphezulu be-crucible yi-2100 ℃, i-raw material particle ububanzi yi-1000 μm, i-porosity yi-0.6, uxinzelelo lokukhula yi-300 Pa, kwaye ixesha lokukhula yi-100 h. . Ubukhulu be-PG bu-5 mm, ububanzi bulingana nobubanzi obungaphakathi be-crucible, kwaye bufumaneka kwi-30 mm ngaphezu kwezinto eziluhlaza. I-sublimation, i-carbonization, kunye ne-recrystallization iinkqubo zommandla wezinto ezikrwada zithathelwa ingqalelo ekubaleni, kwaye ukusabela phakathi kwe-PG kunye nesigaba segesi akuqwalaselwa. Iparamitha yepropathi ebonakalayo enxulumene nokubalwa iboniswe kwiThebhile 1.
Umfanekiso 1 Imodeli yokubala yokulinganisa. (a) Imodeli yentsimi ye-Thermal yokulinganisa ukukhula kwekristale; (b) Ulwahlulo lommandla wangaphakathi weengxaki zomzimba ezinxulumene ne-crucible
Itheyibhile 1 Ezinye iiparamitha ezibonakalayo ezisetyenziswe ekubaleni
Umzobo we-2 (a) ubonisa ukuba ubushushu besakhiwo esine-PG (esichazwe njengesakhiwo se-1) siphezulu kuneso sakhiwo samahhala se-PG (esichazwe njengesakhiwo se-0) ngaphantsi kwe-PG, kwaye siphantsi kwesakhiwo se-0 ngaphezu kwe-PG. Iqondo lobushushu lilonke liyenyuka, kwaye i-PG isebenza njengearhente ekhusela ubushushu. Ngokutsho kweMifanekiso ye-2 (b) kunye ne-2 (c), i-axial kunye ne-radial yeqondo lokushisa kwe-gradient yesakhiwo se-1 kwindawo yezinto eziluhlaza zincinci, ukuhanjiswa kweqondo lokushisa kufana kakhulu, kunye ne-sublimation ye-sublimation epheleleyo. Ngokungafaniyo nendawo yemathiriyeli ekrwada, uMzobo 2(c) ubonisa ukuba iqondo lobushushu beradial kwikristale yembewu yesakhiwo 1 inkulu, enokuthi ibangelwe ziindlela ezahlukeneyo zokuhambisa ubushushu, ezinceda ikristale ikhule kunye nojongano lweconvex. . KuMfanekiso 2(d), iqondo lobushushu kwiindawo ezahlukeneyo kwi-crucible libonisa ukuthambekela okukhulayo njengoko ukukhula kuqhubela phambili, kodwa umahluko wobushushu phakathi kwesakhiwo esingu-0 kunye nolwakhiwo 1 wehla kancinci kwindawo yemathiriyeli ekrwada kwaye ngokuthe ngcembe uyanda kwigumbi lokukhula.
Umzobo 2 Ukuhanjiswa kobushushu kunye notshintsho kwi-crucible. (a) Ukuhanjiswa kobushushu ngaphakathi kwicrucible yesakhiwo 0 (ekhohlo) kunye nesakhiwo 1 (ekunene) kwi-0 h, iyunithi: ℃; (b) Ukuhanjiswa kwamaqondo obushushu kumgca osembindini we-crucible yesakhiwo 0 kunye nesakhiwo 1 ukusuka ezantsi kwezinto ezikrwada ukuya kwikristale yembewu kwi-0 h; (c) Ukuhanjiswa kwamaqondo obushushu ukusuka embindini ukuya kungqameko lwebhotwe kumphezulu wekristale yembewu (A) kunye nomphezulu wezinto ekrwada (B), umbindi (C) nasezantsi (D) nge-0 h, i-axis ethe tye ngu-r. Iradiyasi yekristale yembewu ye-A, kunye neradiya yendawo ekrwada ye-B~D; (d) Utshintsho lobushushu kumbindi wenxalenye ephezulu (A), umphezulu wezinto ekrwada (B) kunye nombindi (C) wegumbi lokukhula lesakhiwo 0 kunye nesakhiwo 1 ku-0, 30, 60, kunye ne-100 h.
Umzobo we-3 ubonisa ukuthuthwa kwezinto eziphathekayo ngamaxesha ahlukeneyo kwi-crucible yesakhiwo se-0 kunye nesakhiwo 1. Inqanaba lokuhamba kwezinto zegesi kwindawo ekrwada kunye negumbi lokukhula liyanda ngokunyuka kwesikhundla, kwaye ukuthuthwa kwezinto eziphathekayo kuncipha njengoko ukukhula kuqhubeka. . Umzobo we-3 ubonisa kwakhona ukuba phantsi kweemeko zokulinganisa, izinto eziluhlaza ziqala ukwenza i-graphitizes eludongeni olusecaleni lwe-crucible kwaye emva koko ngaphantsi kwe-crucible. Ukongeza, kukho i-recrystallization kumphezulu wezinto eziluhlaza kwaye ngokuthe ngcembe ikhula njengoko ukukhula kuqhubeka. Amanani 4 (a) kunye ne-4 (b) abonisa ukuba izinga lokuhamba kwezinto eziphathekayo ngaphakathi kwezinto eziluhlaza liyancipha njengoko ukukhula kuqhubeka, kwaye izinga lokuhamba kwezinto kwi-100 h li malunga ne-50% yomzuzu wokuqala; nangona kunjalo, izinga lokuhamba likhulu kakhulu kumda ngenxa ye-graphitization yezinto eziluhlaza, kwaye izinga lokuhamba kwinqanaba lingaphezulu kwamaxesha angama-10 kwinqanaba lokuhamba kwindawo ephakathi kwi-100 h; Ukongeza, impembelelo ye-PG kwisakhiwo se-1 yenza isantya sokuhamba kwezinto ezibonakalayo kwindawo ekrwada yesakhiwo se-1 ibe ngaphantsi kwesakhiwo se-0. igumbi lokukhula liyancipha ngokuthe ngcembe njengoko ukukhula kuqhubela phambili, kwaye ukuhamba kwezinto ezibonakalayo kwindawo ekrwada kuyaqhubeka nokuhla, okubangelwa ukuvulwa komjelo wokuhamba komoya kumda we-crucible kunye nokuphazamiseka kwe-recrystallization phezulu; kwigumbi lokukhula, izinga lokuhamba kwezinto zesakhiwo 0 liyancipha ngokukhawuleza kwi-30 yokuqala ukuya kwi-16%, kwaye liyancipha kuphela nge-3% kwixesha elilandelayo, ngelixa isakhiwo se-1 sihlala sizinzile kuyo yonke inkqubo yokukhula. Ke ngoko, i-PG inceda ukuzinzisa isantya sokuhamba kwezinto kwigumbi lokukhula. Umzobo we-4 (d) uthelekisa izinga lokuhamba kwezinto ezibonakalayo kwinqanaba lokukhula kwekristale. Ngomzuzu wokuqala kunye ne-100 h, ukuthuthwa kwezinto eziphathekayo kwindawo yokukhula yesakhiwo se-0 yomelele kunoko kwisakhiwo 1, kodwa kusoloko kukho indawo ephezulu yokuhamba kwinqanaba le-0, ekhokelela ekukhuleni okugqithisileyo kumda. . Ubukho be-PG kwisakhiwo soku-1 bucinezela ngempumelelo le nto.
Umzobo 3 Ukuhamba kwezinto kwi-crucible. Ukuhanjiswa (ngasekhohlo) kunye neevektha zesantya (ekunene) zothutho lwegesi kwizakhiwo ze-0 kunye ne-1 ngamaxesha ahlukeneyo, iyunithi yevektha yesantya: m/s
Umzobo 4 Utshintsho kwireyithi yokuhamba kwezinto. (a) Utshintsho kwisantya sokuhamba kwemathiriyeli phakathi kwezinto ezikrwada zesakhiwo 0 kwi-0, 30, 60, kunye ne-100 h, r yiradiyasi yendawo ekrwada; (b) Utshintsho kwisantya sokuhamba kwemathiriyeli phakathi kwezinto ezikrwada zesakhiwo 1 kwi-0, 30, 60, kunye ne-100 h, r yiradiyasi yendawo ekrwada; (c) Utshintsho kwisantya sokuhamba kwezinto ngaphakathi kwegumbi lokukhula (A, B) kunye nangaphakathi kwezinto eziluhlaza (C, D) zezakhiwo 0 kunye ne-1 ngokuhamba kwexesha; (d) Ukuhanjiswa kwesantya sokuhamba kwezinto kufutshane nomphezulu wekristale yembewu yezakhiwo 0 kunye 1 kwi-0 kunye ne-100 h, r yiradiyasi yekristale yembewu.
I-C / Si ichaphazela ukuzinza kwe-crystalline kunye ne-defect density ye-SiC crystal ukukhula. Umzobo we-5 (a) uthelekisa ukuhanjiswa kwe-C / Si kwezakhiwo ezimbini ngexesha lokuqala. Umlinganiselo weC / Si uyancipha ngokuthe ngcembe ukusuka ezantsi ukuya phezulu kwi-crucible, kwaye umlinganiselo we-C / Si wesakhiwo se-1 uhlala uphezulu kunesakhiwo se-0 kwiindawo ezahlukeneyo. Amanani 5(b) kunye no-5(c) abonisa ukuba umlinganiselo we-C/Si ukhula ngokuthe ngcembe ngokukhula, okuhambelana nokunyuka kobushushu bangaphakathi kwisigaba samva sokukhula, ukongezwa kwe-graphitization yezinto ezikrwada, kunye nokusabela kweSi. amacandelo kwisigaba segesi kunye ne-graphite crucible. KuMfanekiso 5 (d), umlinganiselo weC/Si wesakhiwo 0 kunye nesakhiwo 1 zahluke kakhulu ngezantsi kwePG (0, 25 mm), kodwa zihluke kancinane ngaphezu kwePG (50 mm), kwaye umahluko ngokuthe ngcembe ukhula njengoko usondela kwikristale. . Ngokuqhelekileyo, umlinganiselo we-C / Si wesakhiwo se-1 uphezulu, onceda ukuzinzisa ifom ye-crystal kunye nokunciphisa amathuba okuguquka kwesigaba.
Umzobo we-5 Ukusabalalisa kunye notshintsho lwe-C / Si ratio. (a) Ukusabalalisa kwe-C / Si kwi-crucibles yesakhiwo 0 (ekhohlo) kunye nesakhiwo 1 (ekunene) kwi-0 h; (b) Umlinganiselo weC / Si kwimigama eyahlukeneyo ukusuka kumgca ophakathi we-crucible yesakhiwo 0 ngamaxesha ahlukeneyo (0, 30, 60, 100 h); (c) Umlinganiselo weC / Si kwimigama eyahlukeneyo ukusuka kumgca ophakathi we-crucible yesakhiwo se-1 ngamaxesha ahlukeneyo (0, 30, 60, 100 h); (d) Ukuthelekiswa komlinganiselo we-C / Si kwimigama eyahlukeneyo (0, 25, 50, 75, 100 mm) ukusuka kumgca ophakathi we-crucible yesakhiwo 0 (umgca oqinileyo) kunye nesakhiwo 1 (umgca we-dashed) ngamaxesha ahlukeneyo (0, 30, 60, 100 h).
Umzobo we-6 ubonisa utshintsho kwi-particle diameter kunye ne-porosity yemimandla yempahla ekrwada yezakhiwo ezimbini. Umzobo ubonisa ukuba ububanzi bezinto eziluhlaza buyancipha kwaye i-porosity iyanda kufuphi nodonga lwe-crucible, kwaye i-porosity edge iyaqhubeka ikhula kwaye i-particle diameter iyaqhubeka iyancipha njengoko ukukhula kuqhubela phambili. Ubuninzi be-porosity edge malunga ne-0.99 kwi-100 h, kwaye ubuncinci be-particle ububanzi malunga ne-300 μm. I-particle diameter iyanda kwaye i-porosity iyancipha kwindawo ephezulu yezinto eziluhlaza, ehambelana ne-recrystallization. Ubuninzi bendawo ye-recrystallization buyanda njengoko ukukhula kuqhubela phambili, kwaye ubungakanani be-particle kunye ne-porosity iqhubeka nokutshintsha. Ubuninzi be-particle ububanzi bufikelela ngaphezu kwe-1500 μm, kwaye ubuncinci be-porosity yi-0.13. Ukongeza, ekubeni i-PG inyusa ubushushu bendawo ekrwada kwaye i-gas supersaturation incinci, ubukhulu be-recrystallization yenxalenye engaphezulu yento ekrwada yesakhiwo 1 incinci, ephucula izinga lokusetyenziswa kwezinto eziluhlaza.
Umzobo 6 Utshintsho kwi-particle diameter (ekhohlo) kunye ne-porosity (ekunene) yendawo ekrwada yesakhiwo se-0 kunye nesakhiwo se-1 ngamaxesha ahlukeneyo, iyunithi yedayamitha yesuntswana: μm
Umzobo we-7 ubonisa ukuba i-0 i-warps ekuqaleni kokukhula, enokuthi ihambelane nesantya esiphezulu sokuhamba kwezinto ezibangelwa yi-graphitization ye-edge edge. Iqondo le-warping liyancipha ngexesha lenkqubo yokukhula elandelayo, ehambelana nokutshintsha kwesantya sokuhamba kwezinto ezibonakalayo phambi kokukhula kwekristale yesakhiwo 0 kuMfanekiso 4 (d). Kwisakhiwo se-1, ngenxa yempembelelo ye-PG, i-crystal interface ayibonisi ukulwa. Ukongeza, i-PG iphinda yenza isantya sokukhula kwesakhiwo se-1 sisezantsi kakhulu kuneso sakhiwo 0. Ubukhulu beziko lekristale yesakhiwo 1 emva kwe-100 h kuphela i-68% yesakhiwo se-0.
Umzobo we-7 Utshintsho lwe-Interface yesakhiwo 0 kunye nesakhiwo se-crystals ye-1 kwi-30, i-60, kunye ne-100 h.
Ukukhula kweCrystal kwenziwa phantsi kweemeko zenkqubo yokulinganisa kwamanani. Iikristali ezikhuliswe ngesakhiwo 0 kunye nesakhiwo se-1 siboniswe kuMfanekiso 8 (a) kunye noMzobo 8 (b), ngokulandelanayo. I-crystal yesakhiwo i-0 ibonisa i-interface ye-concave, kunye ne-undulations kwindawo ephakathi kunye nokuguqulwa kwesigaba kwinqanaba. I-surface convexity imele iqondo elithile le-inhomogeneity ekuthuthweni kwezixhobo ze-gas-phase, kunye nesiganeko sokuguqulwa kwesigaba sihambelana nomlinganiselo ophantsi weC / Si. I-interface ye-crystal ekhulile ngesakhiwo se-1 i-convex kancinane, akukho tshintsho lwesigaba lufunyenwe, kwaye ubukhulu yi-65% ye-crystal ngaphandle kwe-PG. Ngokuqhelekileyo, iziphumo zokukhula kwe-crystal zihambelana neziphumo zokulinganisa, kunye nokwahlukana okukhulu kwe-radial yeqondo lokushisa kwi-crystal interface yesakhiwo se-1, ukukhula ngokukhawuleza emphethweni kucinezelwe, kwaye izinga lokuhamba kwezinto eziphathekayo lihamba kancinci. Umkhwa jikelele uhambelana neziphumo zokulinganisa amanani.
Umzobo we-8 iikristale zeSiC ezikhule phantsi kwesakhiwo 0 kunye nesakhiwo 1
Ukuqukumbela
I-PG ilungele ukuphuculwa kobushushu bubonke bendawo yemathiriyeli ekrwada kunye nokuphuculwa kokufana kwe-axial kunye ne-radial ubushushu, ukukhuthaza ukuthotywa ngokupheleleyo kunye nokusetyenziswa kwemathiriyeli ekrwada; Umahluko weqondo lobushushu eliphezulu nasezantsi uyenyuka, kwaye i-radial gradient yomphezulu wekristale yembewu iyanda, enceda ukugcina ukukhula kojongano lweconvex. Ngokubhekiselele kugqithiso lobuninzi, ukuqaliswa kwe-PG kunciphisa izinga lokudluliselwa kobuninzi, izinga lokuhamba kwezinto ezibonakalayo kwigumbi lokukhula eliqukethe i-PG litshintsha ngaphantsi kwexesha, kwaye yonke inkqubo yokukhula izinzile. Kwangaxeshanye, i-PG ikwanqanda ngokufanelekileyo ukwenzeka kokudluliselwa kobunzima obugqithisileyo. Ukongeza, i-PG iphinda inyuse umlinganiselo weC / Si wendawo yokukhula, ngakumbi kumda wangaphambili we-crystal interface yembewu, enceda ukunciphisa ukwenzeka kwenguqu yesigaba ngexesha lenkqubo yokukhula. Kwangaxeshanye, impembelelo yokufakelwa kwe-thermal ye-PG inciphisa ukwenzeka kwe-recrystallization kwindawo ephezulu yezinto ezikrwada ukuya kwinqanaba elithile. Ukukhula kwekristale, i-PG iyacotha isantya sokukhula kwekristale, kodwa ujongano lokukhula lubanzi ngakumbi. Ke ngoko, i-PG yindlela esebenzayo yokuphucula imeko yokukhula kweekristale zeSiC kunye nokwandisa umgangatho wekristale.
Ixesha lokuposa: Jun-18-2024