“Kuchinja-chinja ndiwo musimboti wokubudisa pachena chakavanzika chemhindumupindu. Iyo nzira yebudiriro kubva kune yakapusa zvipenyu kuenda kune inotonga zvipenyu zvipenyu inotora zviuru zvemakore. Asi mazana emakore ezviuru zvemazana pane kusvetukira kumberi mukushanduka-shanduka" (Charles Xavier, X-Men, 2000). Kana tikarasa zvese zvesainzi-fiction zvinhu zviripo mumakomiki nemafirimu, saka mazwi aProfesa X ndeechokwadi. Kubudirira kwechimwe chinhu kunoitika zvakaenzana kazhinji yenguva, asi dzimwe nguva kune kusvetuka kune simba guru pakuita kwese. Izvi zvinoshanda kwete chete kushanduka kwezvipenyu, asiwo kushanduka kwekombiyuta, mutyairi mukuru uyo ari vanhu, tsvakurudzo yavo uye zvigadzirwa. Nhasi tichaziva chidzidzo icho, maererano nevanyori varo, ichokwadi chekushanduka-shanduka mune nanotechnology. Masayendisiti kubva kuNorthwestern University (USA) akakwanisa sei kugadzira huviri-dimensional heterostructure, nei graphene neborophene zvakasarudzwa sehwaro, uye zvimiro zvipi zvingave nehurongwa hwakadaro? Chirevo cheboka retsvakurudzo chichatiudza pamusoro peizvi. Enda.
Hwaro hwechidzidzo
Takanzwa izwi rekuti "graphene" kakawanda; ishanduko yemativi maviri ekabhoni, ine dhizaini yekabhoni maatomu 1 atomu gobvu. Asi "borofen" isingawanzoitiki. Iri izwi rinoreva kristaro ine mativi maviri inongosanganisira boron (B) maatomu. Iko kugona kwekuvapo kweborophene kwakatanga kufanotaurwa kumashure pakati pe90s, asi mukuita zvaigoneka kuwana chimiro ichi chete ne2015.
Chimiro cheatomiki cheborophene chine mativi matatu uye ane hexagonal uye mhedzisiro yekudyidzana pakati pemaviri-kati uye akawanda-pakati-pakati-mu-ndege mabhondi, anowanzoitika kune asina kukwana maelekitironi, anosanganisira boron.
*Nembiri-pakati uye mabhondi akawanda tinoreva makemikari bond - kudyidzana kwemaatomu kunoratidza kugadzikana kwemorekuru kana kristaro sechimiro chimwe chete. Semuenzaniso, maviri-center maviri-electron bond anoitika apo maatomu maviri anogovera maerekitironi maviri, uye maviri-center three-electron bond inoitika apo maatomu maviri nemaerekitironi matatu, nezvimwewo.
Kubva pakuona kwenyama, borophene inogona kuva yakasimba uye inoshanduka kupfuura graphene. Zvinotendwa zvakare kuti zvimiro zveborophene zvinogona kubatsira mabhatiri, sezvo borophene ine yakakwirira chaiyo hunyanzvi uye yakasarudzika yemagetsi conductivity uye ion yekufambisa zvivakwa. Zvisinei, panguva ino iyi ingori dzidziso.
Kuva trivalent element*, boron ine kanenge gumi allotropes*. Mune maviri-dimensional fomu, yakafanana polymorphism* inocherechedzwawo.
Trivalent element* inokwanisa kugadzira zvisungo zvitatu zve covalent, iyo valency iri nhatu.
Allotropy* - apo chimwe chemakemikari chinhu chinogona kuratidzwa nenzira yezvinhu zviviri kana kupfuura zviri nyore. Semuenzaniso, carbon - diamond, graphene, graphite, carbon nanotubes, nezvimwewo.
Polymorphism* - kugona kwechinhu kuvapo mune akasiyana makristasi zvimiro (polymorphic modifications). Panyaya yezvinhu zviri nyore, izwi iri rinofanana nerokuti allotropy.
Tichifunga nezve polymorphism iyi yakakura, zvinokurudzirwa kuti borophene inogona kunge iri mukwikwidzi akanakisa kugadzira maviri-dimensional heterostructures, sezvo akasiyana boron bonding masisitimu anofanirwa kudzoreredza lattice yekufananidza zvinodiwa. Sezvineiwo, nyaya iyi yakambodzidzwa chete padanho redzidziso nekuda kwekuomerwa mukubatanidza.
Kune zvakajairwa 2D zvinhu zvakawanikwa kubva kune akawanda akaturikidzana makristasi, vertical heterostructures inogona kuoneka uchishandisa mechanic stacking. Kune rimwe divi, maviri-dimensional lateral heterostructures akavakirwa pazasi-kumusoro synthesis. Atomically precise lateral heterostructures ine mukana wakakura mukugadzirisa heterojunction functional control matambudziko, zvisinei, nekuda kwekubatana kwakabatana, kusakwana kwelattice kufananidzwa kunowanzo konzera nzvimbo dzakafara uye dzisina kurongeka. Naizvozvo, pane zvinogoneka, asi panewo matambudziko mukuzviona.
Mune iri basa, vatsvakurudzi vakakwanisa kubatanidza borophene uye graphene mune imwe mbiri-dimensional heterostructure. Pasinei nekusawirirana kwecrystallographic lattice uye symmetry pakati peborophene negraphene, sequential deposition yekabhoni neboron pane Ag (111) substrate iri pasi pe Ultra-high vacuum (UHV) inoguma neatomu chaiyo chaiyo lateral heterointerfaces ine yakafanotaurwa lattice marongerwo enyika, pamwe nehupamhi hwepamusoro-soro. .
Kugadzirira kudzidza
Asati adzidza iyo heterostructure, yaifanira kugadzirwa. Kukura kwegraphene uye borophene kwaiitwa mune imwe ultra-high vacuum chamber ine dzvinyiriro ye1x10-10 millibars.
Iyo imwe chete crystal Ag (111) substrate yakacheneswa nekudzokororwa kutenderera kweAr+ sputtering (1 x 10-5 millibar, 800 eV, 30 maminetsi) uye kupisa kwekupisa (550 ° C, 45 maminetsi) kuwana atomu yakachena uye flat Ag ( 111) pamusoro.
Graphene yakarimwa neelectron beam evaporation ye pure (99,997%) graphite rod ine dhayamita ye2.0 mm paAg (750) substrate inopisa kusvika 111 °C pakudziya kwazvino kwe ~ 1.6 A uye inomhanyisa voltage ye ~ 2 kV. , iyo inopa emission ikozvino ~ 70 mA uye kabhoni flux ~ 40 nA. Kumanikidza mukamuri kwaive 1 x 10-9 millibars.
Borophene yakarimwa kuburikidza ne electron beam evaporation ye pure (99,9999%) boron rod pane submonolayer graphene paAg (400) yakadziiswa kusvika 500-111 °C. Iyo filament current yaive ~ 1.5 A uye simba rekumhanyisa raive 1.75 kV, iro rinopa emission current ye ~34 mA uye boron flux ye ~10 nA. Kudzvinyirirwa mukamuri panguva yekukura kweborophene kwaiva anenge 2 x 10-10 millibars.
Mhedzisiro yekutsvaga
Mufananidzo #1
Mumufananidzo 1A kuratidzwa STM* mufananidzo weyakakura graphene, uko graphene domains inonyatso kuoneka uchishandisa mepu dI/dV (1B), kupi I и V ndiyo tunneling ikozvino uye sampuli yekufambisa, uye d - density.
STM* - kuongorora tunneling maikorosikopu.
dI/dV mamepu emuenzaniso akatibvumira kuona huwandu hwepamusoro hwenzvimbo dzegraphene zvichienzaniswa neAg(111) substrate. Zvinoenderana nezvidzidzo zvakapfuura, iyo nzvimbo yeAg (111) ine nhanho hunhu, inochinjirwa kune yakanaka simba ne. dI/dV chimiro che graphene (1С), iyo inotsanangura huwandu hwepamusoro hwenzvimbo dzematunhu egraphene pa 1B ku0.3 ev.
Mumufananidzo 1D isu tinogona kuona chimiro che-single-layer graphene, uko muzinga wehuchi lattice uye moiré superstructure*.
Superstructure* - chimiro chechimiro chekristaro komboni inodzokorora pane imwe nguva uye nekudaro inogadzira chimiro chitsva chine imwe nguva yekuchinjisa.
Moire* - superposition yemaviri periodic mesh mapatani pamusoro peumwe neumwe.
Pakudziya kwakadzika, kukura kunotungamira mukuumbwa kwedendritic uye yakaremara graphene domains. Nekuda kwekudyidzana kusina simba pakati pegraphene neiyo substrate iri pasi, kutenderedzwa kwegraphene maererano neiyo Ag (111) isiri yega.
Mushure mekuisa boron, kuongorora tunneling microscopy (1E) yakaratidza kuvapo kwemusanganiswa we borophene uye graphene domains. Zvakare zvinoonekwa mumufananidzo matunhu ari mukati megraphene, ayo akazoonekwa segraphene yakabatana neborophene (inoratidzwa mumufananidzo. Gr/B) Linear zvinhu zvakanangidzirwa mumativi matatu uye zvakapatsanurwa nekona ye120° zvinonyatsooneka munzvimbo iyi (yero miseve).
Mufananidzo #2
Mufananidzo uri 2Afuti 1E, simbisa kutaridzika kwenzvimbo yakasviba yakasviba mugraphene mushure mekuiswa kweboron.
Kuti utarise zvirinani maumbirwo aya nekuziva kwaakabva, mumwe mufananidzo wakatorwa wenzvimbo imwe chete, asi uchishandisa mepu |dlnI/dz| (2B), kupi I - tunnel current, d ndiko density, uye z - probe-sample kupatsanurwa (mukaha pakati peiyo microscope tsono uye sampuli). Kushandiswa kwemaitiro aya kunoita kuti zvikwanise kuwana mifananidzo ine yakakwirira spatial resolution. Iwe unogona zvakare kushandisa CO kana H2 pane microscope tsono yeizvi.
Image Image 2С chifananidzo chinowanikwa uchishandisa STM iyo tip yaive yakashongedzwa neCO. Kuenzanisa kwemifananidzo А, В и С inoratidza kuti maelementi ese eatomu anotsanangurwa semakona matatu akatarisana akajeka anonangidzirwa mumativi maviri asina kuenzana (makona matatu matsvuku neyero pamifananidzo).
Mifananidzo yakakurisa yenzvimbo iyi (2D) inosimbisa kuti zvinhu izvi zviri kubvumirana ne boron dopant tsvina, inotora maviri graphene sublattices, sezvinoratidzwa nepamusoro pezvimiro.
CO kupfekedzwa kwetsono yemicroscope kwakaita kuti zvikwanise kuratidza chimiro chejometri yepepa reborophene (2E), izvo zvingave zvisingabviri kana tsono yaive yakajairika (simbi) isina CO coating.
Mufananidzo #3
Kuumbwa kwe lateral heterointerfaces pakati pe borophene uye graphene (3A) inofanira kuitika kana borophene inokura padivi pegraphene domains inotova neboron.
Masayendisiti anoyeuchidza kuti lateral heterointerfaces yakavakirwa pagraphene-hBN (graphene + boron nitride) ine lattice kusachinja-chinja, uye heterojunctions yakavakirwa pane shanduko yesimbi dichalcogenides ine symmetry kusachinja-chinja. Panyaya yegraphene/borophene, mamiriro acho akati siyanei - ane mashoma maumbirwo akafanana maererano nelattice constants kana crystal symmetry. Zvisineyi, zvisinei neizvi, iyo lateral graphene/borophene heterointerface inotaridza kuenderana kweatomu yakakwana, ine boron row (B-row) nzira dzakaenderana ne zigzag (ZZ) nzira dzegraphene (3A) On 3B mufananidzo wakakudzwa weZZ nharaunda yeheterointerface inoratidzwa (mitsetse yebhuruu inoratidza zvinhu zvemukati zvinoenderana ne boron-carbon covalent bonds).
Sezvo borophene inokura pane tembiricha yakaderera kana ichienzaniswa negraphene, micheto ye graphene domain haigone kuve nekufamba kwakakwira kana ichigadzira heterointerface ine borophene. Naizvozvo, iyo inenge yeatomu chaiyo chaiyo heterointerface ingangove mhedzisiro yekumisikidzwa kwakasiyana uye hunhu hwemultisite boron bond. Kuongorora tunneling spectroscopy spectra (3С) uye musiyano mugero conductivity (3D) kuratidza kuti shanduko yemagetsi kubva kugraphene kuenda kuborophene inoitika pamusoro pechinhambwe che ~ 5 Å pasina inooneka inooneka nyika.
Mumufananidzo 3E Anoratidzwa matatu matatu ekuvheneka tunneling spectroscopy spectra akatorwa pamwe nemitsara mitatu yakadhirowewa mu3D, inosimbisa kuti iyi pfupi yemagetsi shanduko haina hanya kune emuno maumbirwo ezviso uye inofananidzwa neiyo paborophene-silver interfaces.
Mufananidzo #4
Graphene kupindirana* zvakare yakambodzidzwa zvakanyanya, asi kushandurwa kweanopindirana kuita echokwadi 2D mapepa hakuwanzo.
Kudyidzana* - inodzoreredzwa kuisirwa kwemorekuru kana boka remamorekuru pakati pemamwe mamorekuru kana mapoka emamorekuru.
Iyo diki yeatomu yeradius yeboron uye kupindirana kusina kusimba pakati pegraphene neAg(111) kunopa zano rinobvira kupindirana kwegraphene neboron. Mumufananidzo 4A humbowo hunoratidzwa kwete chete hwekupindirana kweboron, asiwo nekuumbwa kweiyo vertical borophene-graphene heterostructures, kunyanya mativi matatu akakomberedzwa negraphene. Mucherechedzo wehuchi unocherechedzwa panzvimbo ino yetriangular inosimbisa kuvepo kwegraphene. Nekudaro, iyi graphene inoratidza yakaderera yenzvimbo density yematunhu pa -50 meV zvichienzaniswa neyakatenderedza graphene (4B) Kuenzaniswa negraphene zvakananga paAg (111), hapana humbowo hwekuwanda kwenzvimbo dzematunhu mune spectrum. dI/dV (4C, blue curve), inoenderana neAg(111) surface state, ndihwo humbowo hwekutanga hwekupindirana kweboron.
Zvakare, sezvinotarisirwa kupindirana kwechidimbu, graphene lattice inoramba ichienderera mberi mukati meiyo lateral interface pakati pegraphene nenzvimbo yetriangular (4D - inoenderana nenzvimbo ine rectangular pa 4A, yakatenderedzwa mumutsara une madota matsvuku). Mufananidzo unoshandisa CO pane microscope tsono yakasimbisawo kuvapo kwe boron substitution tsvina (4E - inoenderana nenzvimbo ine rectangular pa 4A, yakatenderedzwa mumutsara une madota eyero).
Microscope tsono pasina kana coating dzakashandiswawo panguva yekuongorora. Muchiitiko ichi, zviratidzo zveimwe-dimensional linear zvinhu zvine periodicity ye5 Å zvakaratidzwa mune yakabatana graphene domains (4F и 4G) Aya ma-dimensional maitiro akafanana nemitsara yeboron mumuenzaniso weborophene. Pamusoro peseti yemapoinzi inoenderana negraphene, iyo Fourier inoshandura yemufananidzo kuita 4G inoratidza peya yemapoinzi emakona anoenderana ne3 Å x 5 Å rectangular lattice (4H), iri muchibvumirano chakanakisa neiyo borophene modhi. Uye zvakare, iyo yakacherechedzwa katatu kutaridzika kweiyo mutsara wemutsara zvinhu (1E) inobvumirana zvakanaka nechimiro chakafanana chakacherechedzwa pamashiti eborophene.
Zvese zvakacherechedzwa izvi zvinokurudzira kupindirana kwegraphene neborophene padhuze nekumicheto kweAg, izvo zvinozotungamira mukuumbwa kweyakamira borophene-graphene heterostructures, iyo inogona kunyatsozivikanwa nekuwedzera kufukidzwa kwekutanga kwegraphene.
4I chiratidziro chechimiro cheyakamira heterostructure pa 4H, uko kwakanangana nemutsara weboron (museve wepingi) wakanyatso kuenderana neinotenderera zigzag yegraphene (museve mutema), zvichigadzira tenderera inotenderera yakatwasuka heterostructure.
Kuti uwane rumwe ruzivo rwakadzama rwema nuances echidzidzo, ini ndinokurudzira kutarisa и kwaari.
Epilogue
Chidzidzo ichi chakaratidza kuti borophene inokwanisa chaizvo kugadzira lateral uye vertical heterostructures ine graphene. Zvirongwa zvakadaro zvinogona kushandiswa mukugadzirwa kwemhando itsva dzezvinhu zviviri-dimensional zvinoshandiswa mu nanotechnology, flexible and wearable electronics, pamwe chete nemhando itsva dze semiconductors.
Vatsvagiri ivo pachavo vanotenda kuti budiriro yavo inogona kuve yekusundidzira kune simba kumberi kwemagetsi ane hukama matekinoroji. Zvisinei, zvichiri kuoma kutaura chokwadi kuti mashoko avo achava echiporofita. Parizvino, pachine zvakawanda zvinoda kuongororwa, kunzwisiswa uye kugadzirwa kuitira kuti idzo pfungwa dzenhema dzesainzi dzinozadza pfungwa dzesainzi dzive chokwadi chakazara.
Ndatenda nekuverenga, garai muchida kuziva uye muve nevhiki yakanaka vakomana. 🙂
Ndinokutendai nekugara nesu. Unoda zvinyorwa zvedu here? Unoda kuona zvimwe zvinonakidza zvemukati? Titsigire nekuisa odha kana kukurudzira kushamwari, 30% kuderedzwa kwevashandisi veHabr pane yakasarudzika analogue yekupinda-level maseva, iyo yakagadzirwa nesu kuti iwe: (inowanikwa neRAID1 uye RAID10, kusvika ku24 cores uye kusvika ku40GB DDR4).
Dell R730xd kaviri zvakachipa? Chete pano muNetherlands! Dell R420 - 2x E5-2430 2.2Ghz 6C 128GB DDR3 2x960GB SSD 1Gbps 100TB - kubva pamadhora makumi mapfumbamwe nemapfumbamwe! Verenga nezve
Source: www.habr.com