1. IChemistry eyiSiseko kunye noYilo lweCrystallographic yeTeksi ESITHANDATHU
1.1 Isakhelo se-Boron-Rich kunye ne-Electronic Band Framework
(Calcium Hexaboride)
I-calcium hexaboride (ITEKISI ₆) yintsimbi ye-stoichiometric evela kwindlela enqabileyo-yomhlaba kunye ne-alkaline-earth hexaborides., yahlulwa ngomxube wayo wohlobo olulodwa lwe-ionic, covalent, kunye neempawu zokudibanisa isinyithi.
Isakhiwo sayo sekristale samkela i-cubic CsCl-type lattice (iqela lesithuba Pm-3m), apho iiathom zekhalsiyam zihlala kwimiphetho yetyhubhu kunye nesakhelo esinemigangatho emithathu entsonkothileyo yeboron octahedra (B ₆ izixhobo) uhlala kwindawo yomzimba.
Ibhoron nganye i-octahedron yenziwe ngeeathom zebhoron ezintandathu ezibanjelwe ngokubambisana kulungiselelo olulingene kakhulu., ukudala eqinile, Uthungelwano lwe-electron-deficient exhaswa yindleko yokudluliselwa kwi-athomu ye-electropositive calcium.
Olu dluliselo lweendleko lukhokelela kwibhendi yothumelo elayishiwe ngokungaphelelanga, Ukunika iteksi ezintandathu ngeconductivity yombane ephezulu ngokungaqhelekanga kwimveliso yeceramic– ngokomyalelo we 10 ⁵ S/m kwinqanaba lobushushu begumbi– nangona ibhendi yayo enkulu emalunga ne-1.0– 1.3 I-eV njengoko isekwe ngokufunxwa kwamehlo kunye nezifundo zophando lwe-photoemission.
Ukuqala kwale mfihlelo– conductivity eliphezulu ekhoyo icala-by-icala kunye bandgap kakhulu– ibingumxholo wofundo olubanzi, ngeekhonsepthi ezicebisa ukubonakala kweziphene zangaphakathi, umphezulu conductivity, okanye iindlela zokuqhuba ze-polaronic ezibandakanya ukudibanisa i-electron-phonon yendawo.
Ubalo lwakutsha nje lwemigaqo yokuqala lugcina uyilo apho ibhendi yothumelo ifumana ubukhulu becala kwiCa 5d orbitals., ngelixa ibhendi ye-valence ilawulwa yi-B 2p ithi, ukuvelisa i-slim, band dispersive ekhuthaza intshukumo electron.
1.2 Ukhuseleko lwe-Thermal kunye noomatshini kwiMiba eBabekileyo
Njengeceramic echasayo, TAXICAB ₆ ibonisa ukuzinza okungaqhelekanga kwe-thermal, ngeqondo lokunyibilika eligqithileyo 2200 ° C kunye nokwehla kobunzima obungenamsebenzi kwi-inert okanye kwi-vacuum cleaner useto ukuya kuthi ga 1800 °C.
Ubushushu bayo obuphezulu bokuqhekeka kunye noxinzelelo oluncitshisiweyo lomphunga luyenza ilungele ubushushu obuphezulu boyilo kunye nezicelo ezisebenzayo apho ukunyaniseka kwezinto phantsi koxinzelelo lwe-thermal kubalulekile..
Ngoomatshini, I-CaB ₆ ineVickers yokuqina emalunga ne-25– 30 GPA, ukuyibeka phakathi kwezona ndawo zinzima zaziwayo kwaye ibonakalisa amandla eB– B iibhondi covalent ngaphakathi kwesakhelo octahedral.
Izinto eziphathekayo nazo zibonisa i-coefficient ephantsi yokwandiswa kwe-thermal (~ 6.5 × 10 ⁻⁶/ K), igalelo kuxhathiso olubalaseleyo lobushushu bobushushu– umgangatho obalulekileyo weendawo ezisekwe kubushushu obukhawulezayo kunye nemijikelo yokupholisa.
Ezi zakhiwo zokuhlala, kudityaniswe nokungangeni kweekhemikhali ukuya kwiintsimbi ezityhidiweyo kunye ne-slags, ixhasa ukusetyenziswa kwayo kwiicrucibles, izitya ze-thermocouple, kunye neeyunithi zokuvavanya ubushushu obuphezulu kwiindawo zetsimbi kunye nezoshishino.
( Calcium Hexaboride)
Ngaphezu koko, I-TAXICAB ₆ ibonisa ukuxhathisa okukhethekileyo kwi-oxidation edweliswe ngezantsi 1000 °C; nangona kunjalo, ngaphezulu kwalo mda, umphezulu we-oxidation kwi-calcium borate kunye ne-boric oxide inokwenzeka, ifuna ukugqitywa kokhuseleko okanye ulawulo lokusebenza kwi-ambiences oxidizing.
2. Iindlela zokuHlanganisa kunye noYilo lweMicrostructural
2.1 UbuGcisa obuQhelekileyo kunye noBuchule bokuFaka
Ukwenziwa kweeteksi ezicoceke kakhulu ezintandathu zihlala zibandakanya iimpendulo eziqinileyo phakathi kwe-calcium kunye ne-boron precursors kumaqondo obushushu aphezulu..
Iindlela eziqhelekileyo ziquka ukuhla kwe-calcium oxide (CaO) kunye ne-boron carbide (B ₄ C) okanye i-boron ebalulekileyo phantsi kweemeko ze-inert okanye i-vacuum kumanqanaba obushushu phakathi 1200 ° C kunye 1600 °C. ^
. Impendulo kufuneka ilawulwe ngocoselelo ukunqanda ukwakheka kwezigaba ezongezelelweyo ezifana neteksi yesine okanye iteksi EMBINI., enokuthi yonakalise ukusebenza kombane kunye noomatshini.
Iindlela ezizezinye zibandakanya ukuhla kwe-carbothermal, ukunyibilika kwe-arc, kunye ne-mechanochemical synthesis usebenzisa i-high-energy ball milling, enokunciphisa amanqanaba okushisa okuphendula kunye nokunyusa i-powder homogeneity.
Kumacandelo e-ceramic ashinyeneyo, iindlela ze-sintering ezifana nokucofa okushushu (HP) okanye uqalise ukutshisa iplasma (SPS) zisetyenziselwa ukufezekisa ukuxinana kwethiyori ngelixa zinciphisa ukukhula okuziinkozo kunye nokugcina i-microstructures enkulu.
SPS, ngokukodwa, yenza kube lula ukudibanisa ngokukhawuleza kumaqondo obushushu asezantsi kunye namaxesha amafutshane okuhlala, ukunciphisa ingozi ye-calcium volatilization kunye nokugcina i-stoichiometry.
2.2 I-Doping kunye neMiba yeKhemistri yoLungiso lweKhaya
Enye yezona nkqubela zibalulekileyo kwiCaB ₆ kuphononongo lophando ibe kukukwazi ukulungelelanisa indawo yokuhlala yedijithali kunye ne-thermoelectric okanye iipropathi zorhwebo ngedoping ngabom kunye nobunjineli obungenasiphako..
Ukutshintshwa kwe-calcium nge-lanthanum (I), i-cerium (Ce), okanye ezinye izinto ezinqabileyo zomhlaba zazisa ababoneleli bentlawulo abongezelelweyo, ukwandisa kakhulu ukuhanjiswa kombane kunye nokwenza ukuba kwenzeke kwizenzo ze-n-uhlobo lwe-thermoelectric.
Ngokufanayo, Ukutshintshwa ngokuyinxenye kweboron ngekhabhoni okanye initrogen kunokwenza ubukhulu belizwe kufutshane nenqanaba leFermi, ukuphucula i-coefficient ye-Seebeck kunye nenani elipheleleyo le-thermoelectric yexabiso (ZT).
Imiba yendalo, ngakumbi imisebenzi ye-calcium, kwakhona ukudlala umsebenzi obalulekileyo ekumiseleni conductivity.
Uphononongo lophando lubonisa ukuba iteksi ezintandathu zihlala zibonisa ukunqongophala kwekhalsiyam ngenxa yokuguquguquka kulo lonke uhlobo lobushushu obuphezulu, okukhokelela ekuqhutyweni komngxuma kunye neentshukumo ze-p kwezinye iisampuli.
Ukulawula i-stoichiometry ngolawulo oluchanekileyo lwe-ambience kunye nokufakwa kwe-encapsulation ngexesha lokudibanisa kungenxa yeso sizathu kubalulekile ekusebenzeni ngokuphinda-phindayo kusetyenziso lwedijithali kunye noguqulo lwamandla..
3. IiPropati eziSebenzayo kunye neFantasm yoMzimba kwiTeksi ₆
3.1 Ukukhutshwa kwe-Electron ekhethekileyo kunye nezicelo zokukhupha kwiNdawo
I-CaB ₆ idume ngomsebenzi wayo ophantsi– ngokurhabaxa 2.5 eV– phakathi kwezona zifikelelekayo kwiimveliso zeceramic ezizinzileyo– iyenza ibe ngumgqatswa okhethekileyo kwi-thermionic kunye ne-electron emitters yendawo.
Le propati yokuhlala okanye yorhwebo ivela kumxube woxinaniso lwe-electron ephezulu kunye nolungiselelo lwe-dipole yomphezulu onenzuzo, Ivumela ukukhutshwa kwe-electron esebenzayo kumanqanaba obushushu ancitshisiweyo ngokufanelekileyo xa kuthelekiswa neemveliso eziqhelekileyo ezifana ne-tungsten (umsebenzi umsebenzi ~ 4.5 eV).
Ngenxa yale nto, I-TAXICAB SIX-based cathodes isetyenziswa kwizixhobo ze-electron beam, kuquka ukuskena i-electron microscopic lens (YILUPHI), iiwelder ze-electron beam, kunye neetyhubhu ze-microwave, apho banikezela ubomi obude, ukunciphisa amanqanaba okushisa okusebenzayo, kunye nokukhanya okuphezulu kuneemitter eziqhelekileyo.
Iteksi elungiselelwe imiboniso bhanyabhanya emithandathu kunye neenwele zikomeleza ngakumbi ukusebenza kwentsimi ngokunyusa ukuqina kwendawo yombane kwiimbono ezibukhali., ukwenza kube lula ukusebenza kwe-cathode epholileyo kwi-microelectronics yesicoci se-vacuum kunye ne-flat-panel display screens.
3.2 Ukufunxwa kweNeutron kunye neMisebenzi yoKhuselo lweMitha
Ubuchule obongezelelweyo obubalulekileyo be-CaB ₆ bulele kwisakhono sayo sokufunxa neutron, ikakhulu ngenxa ye-thermal neutron yokubamba cross-candelo le-¹⁰ B isotope (3837 izisele).
Ibhoron yendalo ibandakanya malunga 20% ¹⁰ B, kunye neCaB6 etyetyisiweyo ngemathiriyeli ¹⁰ B enkulu inokulungiselelwa ukhuseleko oluphuculweyo olusebenzayo lweneutron.
Xa ineutron irekhodwa yi ¹⁰ B nucleus, iqalisa intshukumo yenyukliya ¹⁰ B(n, a)⁷ Li, ukukhulula amasuntswana e-alpha kunye ne-lithium ion ezimiswe ngokufanelekileyo ngaphakathi kwezinto, ukuguqula imitha ye-neutron ibe ngamaqhekeza ahlawuliswayo angenabungozi.
Oku kwenza iteksi ₆ ibe yimathiriyeli enomtsalane kumalungu afunxa ineutron kwizityalo zamandla eathom., ugcino lwegesi olutyaliwe, kunye neenkqubo zokufunyanwa kwemitha.
Ngokungafaniyo ne-boron carbide (B ₄ C), enokudumba phantsi kwe-neutron irradiation ngenxa ye-helium build-up, I-CaB ₆ ibonisa ukhuseleko oluphezulu kunye nokumelana nomonakalo wemitha, ngokukodwa kumaqondo obushushu anyusiweyo.
Iqondo eliphezulu lokunyibilika kwayo kunye nokuqina kweekhemikhali kongeza ukuphucula ukusebenza kwayo kwixesha elide lokusasazwa kwindawo yenyukliya..
4. Ukuvela kunye nezicelo zoShishino kwi-Advanced Technologies
4.1 Uguqulo lwe-Thermoelectric Energy kunye neNkunkuma yokuBuyisa ubushushu
Ukudityaniswa kombane ophezulu wokuqhuba, imodareyitha Seebeck, kunye nokunciphisa i-thermal conductivity (ngenxa yokusasazeka kwephonon ngesakhelo sebhoron yoncedo) izicwangciso CaB ₆ njengento ethembisayo ye-thermoelectric yesixhobo- ukuya ekuvuneni amandla obushushu obuphezulu.
Iintlobo ezahlukeneyo, ingakumbi iLa-doped taxi ESITHANDATHU, babonise ixabiso le-ZT ligqwesile 0.5 e 1000 K, ngomthamo wophuculo olungaphezulu ngokucwangciswa kwe-nanostructuring kunye noyilo lomda wokuziinkozo.
Ezi mveliso zifunyanwa ukuba zisetyenziswe kwiijenereyitha ze-thermoelectric (TEGs) eziguqula inkunkuma eyingozi ifudumele– ukusuka kwiinkqubo zokufudumeza intsimbi, iinkqubo zokukhupha, okanye izityalo zombane– kumandla ombane aluncedo.
Ukhuseleko lwabo emoyeni kunye nokuchasana ne-oxidation kumanqanaba obushushu aphakanyisiweyo kunika inzuzo enkulu ngaphezu kwe-thermoelectrics yendabuko njenge-PbTe okanye i-SiGe, nto leyo efuna umoya okhuselayo.
4.2 Advanced Coatings, Iimbumba, kunye ne-Quantum Material Platforms
Usetyenziso oluninzi oludlulileyo, I-TAXICAB ₆ idityaniswe ngqo kwizinto ezidibeneyo kunye neeleya eziluncedo ukomeleza ukuqina, nxiba ukumelana, kunye neempawu zokukhupha i-electron.
Njengokuba, I-TAXI SIX-i-aluminiyam enobunzima bokukhanya obuphuculweyo okanye iikhompawundi zematrix yobhedu zibonisa amandla angcono kunye nokhuseleko lobushushu kwi-aerospace kunye nezicelo zoqhagamshelwano zombane..
Imiboniso bhanyabhanya ebhityileyo yeteksi ezintandathu ezikhutshelwe ngokutshiza okanye i-pulsed laser deposition isetyenziswa kwiingubo ezomeleleyo., imiqobo yokusasaza, kunye neengqimba ezikhuphayo kwizixhobo zedijithali zevacuum.
Okongeziweyo mva nje, Ikristale enye kunye nemiboniso bhanyabhanya ye-epitaxial yeteksi ezintandathu ngokwenene itsalele umdla kumbandela wefiziksi ngenxa yeerekhodi zokuziphatha okungalindelekanga., ebandakanya amabango e-ferromagnetism yobushushu begumbi kwiisampulu ezifakwe emanzini– nangona oku kuqhubeka kuthandabuzeka kwaye kusenokwenzeka ukuba kudityaniswe nemagnethi eyenziwe sisiphene endaweni yocwangco olude..
Noba kutheni, I-CaB ₆ isebenza njengenkqubo eyimodeli yokufunda iziphumo zoqhagamshelo lwe-electron, amazwe edijithali, kunye nothutho lwequantum kwi-boride latticeworks enzima.
Isishwankathelo, Ikhalsiyam hexaboride ingumzekelo wokudityaniswa kokuqina kolwakhiwo kunye noncedo olusebenzayo kwiiseramikhi eziphucukileyo..
Umxube wayo oyingqayizivele we-conductivity ephezulu yombane, ukuzinza kwe-thermal, ukufunxwa kwe-neutron, kunye neepropathi ezikhutshwa yi-electron zendawo yokuhlala okanye yorhwebo ivumela usetyenziso kuwo wonke amandla, zenyukliya, elektroniki, kunye nemveliso amagama esizinda sesayensi.
Njengoko izicwangciso ze-synthesis kunye ne-doping ziqhubeka ziqhubela phambili, I-CaB ₆ ibekwe ukuba idlale umsebenzi obaluleke kakhulu kubuchwephesha besizukulwana esilandelayo obufuna ukusebenza ngokufanelekileyo phantsi kweemeko ezinzima..
5. Umthengisi
I-TRUNANO ngumthengisi we-Spherical Tungsten Powder ene-over 12 iminyaka yamava kwi-nano-building energy yogcino kunye nophuhliso lwe-nanotechnology. Iyayamkela intlawulo ngekhadi letyala, T/T, I-West Union kunye ne-Paypal. I-Trunnano iya kuthumela iimpahla kubathengi phesheya ngokusebenzisa i-FedEx, DHL, ngomoya, okanye ngolwandle. Ukuba ufuna ukwazi ngakumbi ngeSpherical Tungsten Powder, nceda uzive ukhululekile ukuqhagamshelana nathi kwaye uthumele umbuzo([email protected]).
Iithegi:
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