"Isbeddelku waa furaha daah-furka sirta horumarka. Jidka horumarka laga bilaabo noolaha ugu fudud ilaa nooca noole ee ugu sarreeya wuxuu socdaa kumanaan sano. Laakiin boqol kun oo sano kasta waxaa jira horumar fiiqan oo horumarsan" (Charles Xavier, X-Men, 2000). Haddaynu iska tuurno dhammaan walxaha khayaaliga sayniska ee ku jira majaajilada iyo filimada, markaas erayada Professor X waa run. Horumarka shay wuxuu u socdaa si siman inta badan, laakiin mararka qaarkood waxaa jira boodo kuwaas oo saameyn weyn ku leh habka oo dhan. Tani ma khusayso oo kaliya horumarinta noocyada, laakiin sidoo kale horumarinta tiknoolajiyada, darawalka ugu weyn ee ay tahay dadka, cilmi-baaristooda iyo hal-abuurkooda. Maanta waxaan baran doonaa daraasad, sida ay qabaan qorayaashu, waa horumar dhab ah oo ku saabsan nanotechnology. Sidee bay saynisyahano ka socda Jaamacadda Waqooyi-galbeed (USA) u maareeyeen inay abuuraan qaab-dhismeed cusub oo laba-cabbir ah, sababta graphene iyo borophene loo doortay inay aasaas u noqdaan, iyo maxay guryaha ay yeelan karaan nidaamkan? Warbixinta kooxda cilmi-baarista ayaa nooga sheegi doonta arrintan. Tag
Saldhig cilmi baaris
Waxaan maqalnay ereyga "graphene" marar badan; waa wax ka beddel laba-geesood ah oo kaarboon ah, oo ka kooban lakabka atamka kaarboonka 1 atamka dhumucdiisuna tahay. Laakiin "borofen" waa mid aad dhif u ah. Eraygani waxa uu tilmaamayaa kiristaalo laba-cabbir ah oo ka kooban atamka boron (B). Suurtagalnimada jiritaanka borophene ayaa markii ugu horreysay la saadaaliyay bartamihii 90-meeyadii, laakiin ficil ahaan qaabkan waxaa la helay kaliya 2015.
Qaab dhismeedka atomiiga ee borophene waxa uu ka kooban yahay saddex geesood iyo laba geesood, waana natiijada ka dhalatay isdhexgalka ka dhexeeya labada xarumood iyo xudunta badan ee isku xidhka diyaaradda, kaas oo aad u caadi u ah curiyeyaasha elektarooniga ah, oo ay ku jiraan boron.
*Marka la eego bonds-ka laba-xarumood iyo mid-xaruneedyo badan waxaanu ula jeednaa curaarta kiimikaad - isdhexgalka atomyada ee tilmaamaya xasilloonida molecule ama crystal sida hal dhisme. Tusaale ahaan, dammaanadda laba-xarumood ee laba-electron waxay dhacdaa marka 2 atomi ay wadaagaan 2 electrons, iyo xidhidh laba-xarun ah oo saddex-electron ah ayaa yimaada marka 2 atom iyo 3 electrons, iwm.
Marka laga eego dhinaca jirka, borophene waxaa laga yaabaa inuu ka xoog badan yahay oo ka dabacsan yahay graphene. Waxa kale oo la aaminsan yahay in dhismayaasha borophene ay noqon karaan dhammaystir wax ku ool ah baytariyada sababtoo ah borophene waxay leedahay awood gaar ah oo gaar ah iyo habdhaqanka elektiroonigga ah ee gaarka ah iyo sifooyinka gaadiidka ion. Si kastaba ha ahaatee, hadda tani waa kaliya aragti.
Ahaansho element trivalent*, boron waxay leedahay ugu yaraan 10 allotropes*. Qaab laba-cabbir ah, oo la mid ah polymorphism* sidoo kale waa la arkay.
Curiyaha Trivalent* awood u leh samaynta saddex bonds covalent, valency taas oo ah saddex.
Allotropy* - marka hal curiye kiimiko ah lagu soo bandhigi karo qaab laba ama ka badan oo walxaha fudud ah. Tusaale ahaan, kaarboon - dheeman, graphene, graphite, kaarboon nanotubes, iwm.
Polymorphism* - Awoodda walaxda inay ku jiraan qaabab kala duwan oo crystal ah (wax ka beddelka polymorphic). Marka laga hadlayo walxaha fudud, ereygani wuxuu la mid yahay allotropy.
Marka la eego polymorphism-ka ballaaran, waxaa la soo jeediyay in borophene laga yaabo inay noqoto musharax aad u fiican oo abuuraya qaab-dhismeedyada cusub ee laba-geesoodka ah, maadaama qaababka kala duwan ee boron-ku-xidhka ay tahay inay dejiyaan shuruudaha u dhigma. Nasiib darro, arrintan ayaa markii hore si gaar ah loo darsay heer aragtiyeed sababtoo ah dhibaatooyinka soo-saarka.
Qalabka 2D ee caadiga ah ee laga helo kiristaalo lakabka badan, qaab-dhismeedka heterostructures toosan ayaa lagu xaqiijin karaa iyadoo la adeegsanayo isugaynta farsamada. Dhanka kale, qaab-dhismeedka heterostructures ee laba-geesoodka ah waxay ku saleysan yihiin isku-dhafka hoose. Atomically sax ah heterostructures lateral ayaa leh awood weyn oo lagu xallinayo dhibaatooyinka kontoroolka shaqeynta heterojunction, si kastaba ha ahaatee, isku xirnaanta wadajirka ah awgeed, isbarbardhigga shabagga aan dhammaystirnayn wuxuu caadi ahaan keenaa is-dhexyaal ballaadhan oo khalkhalsan. Sidaa darteed, waxaa jira suurtagal, laakiin sidoo kale waxaa jira dhibaatooyin xagga xaqiijinta.
Shaqadan, cilmi-baarayaashu waxay ku guuleysteen in ay isku daraan borophene iyo graphene mid ka mid ah heterostructure laba-cabbir ah. In kasta oo isku-dheeli-tirnaan la'aanta shabkada crystallographic iyo summaynta u dhaxaysa borophene iyo graphene, dhigista isku xigxiga ee kaarboon iyo boron dulsaar Ag(111) substrate hoos yimaada vacuum ultra-high (UHV) waxay keentaa ku dhawaad atomically heterointerfaces lateral oo leh jaangooyo lattice ah, iyo sidoo kale heterointerfaces toosan. .
Diyaarinta daraasadda
Ka hor inta aan la baranin heterostructure, waa in la been abuuraa. Koritaanka graphene iyo borophene waxaa lagu sameeyay qol faaruq ah oo aad u sarreeya oo leh cadaadis 1x10-10 millibars.
Substrate-ka hal crystal Ag (111) waxaa lagu nadiifiyay wareegyada soo noqnoqda ee Ar + sputtering (1 x 10-5 millibar, 800 eV, 30 daqiiqo) iyo kuleylka kuleylka (550 ° C, 45 daqiiqo) si loo helo atomically nadiif ah oo siman Ag ( 111) oogada..
Graphene waxaa lagu beeray uumi koronto elektaroonig ah oo saafi ah (99,997%) ul garaaf ah oo leh dhexroor 2.0 mm dhexroor Ag (750) substrate kuleyl ilaa 111 °C wakhtiga kuleylka ~ 1.6 A iyo korantada dardargelinta ~ 2 kV , kaas oo siiya sii daynta hadda ah ~ 70 mA iyo socodka kaarboon ~ 40 nA. Cadaadiska qolka wuxuu ahaa 1 x 10-9 millibars.
Borophene waxa lagu koray uumi koronto oo uumi saafi ah (99,9999%) boron ushii dusheeda graphene submonolayer on Ag (400) kuleyl ilaa 500-111 °C. Xakamaynta fiiladu waxay ahayd ~ 1.5 A iyo korantada dardargelinta waxay ahayd 1.75 kV, taas oo siinaysa qiiqa hadda jira ~ 34 mA iyo qulqulka boron ee ~ 10 nA. Cadaadiska qolka inta lagu jiro koritaanka borophene wuxuu ahaa qiyaastii 2 x 10-10 millibars.
Natiijooyinka cilmi-baarista
Sawirka #1
Sawirka 1A tusay STM* sawir graphene koray, halkaas oo xayndaabyada graphene sida ugu wanaagsan loogu sawiray khariidad dI/dV (1Bxagee I и V waa barokaca hadda tunnel-ka iyo muunada, iyo d - cufnaanta.
STM* - mikroskoob ee tunneling scanning.
dI/dV Khariidadaha muunada ayaa noo ogolaatay inaan aragno cufnaanta maxalliga ah ee gobollada graphene marka la barbar dhigo Ag(111) substrate. Sida laga soo xigtay daraasadihii hore, xaaladda dusha sare ee Ag (111) waxay leedahay sifo tallaabo ah, oo loo wareejiyay dhinaca tamarta wanaagsan dI/dV spectrum ee graphene (1S), taasoo sharxaysa cufnaanta sare ee deegaanka ee gobolada graphene on 1B 0.3 eV.
Sawirka 1D waxaan arki karnaa qaab dhismeedka graphene hal-lakab ah, halkaas oo shabagga malabka iyo dhismaha sare ee moire*.
Qaab-dhismeedka sare* - muuqaal ka mid ah qaab-dhismeedka xayndaab crystalline ah oo soo noqnoqda wakhti go'an oo sidaas abuura qaab-dhismeed cusub oo leh xilli beddelaad ka duwan.
Moire* - superposition of laba hannaan mesh xilliyeedka on top of midba midka kale.
Heerkulka hoose, koritaanku wuxuu keenaa samaynta dendritic iyo qaybaha garaafka cilladaysan. Isdhexgalka daciifka ah ee ka dhexeeya graphene iyo substrate-ka hoose awgeed, iswaafajinta wareega ee graphene marka loo eego Ag(111) hoose ma aha mid gaar ah.
Ka dib dhigista boron, iskaanka microscopy tunnel-ka1E) waxay muujisay jiritaanka isku-darka borophene iyo graphene domains. Waxa kale oo ka muuqda sawirka gobollo ku jira graphene, kuwaas oo markii dambe loo aqoonsaday inay yihiin graphene oo isku dhafan borophene (ka muuqda sawirka Gr/B). Cutubyo toosan oo ku jihaysan saddex jiho oo u kala soocan xagal 120° ayaa iyaguna si cad uga muuqda goobtan ( fallaadho huruud ah).
Sawirka #2
Sawir ku yaal 2Asida 1E, Xaqiiji muuqaalka niyad-jabka mugdiga ah ee graphene ka dib marka boron la dhigo.
Si loo baaro qaababkan oo loo ogaado halka ay ka yimaadeen, sawir kale ayaa laga qaaday isla goobtaas, laakiin la isticmaalayo maab |dlnI/dz| (2B), halkee I - hadda tunnel, d waa cufnaanta, iyo z - kala-soocidda muunadda baaritaanka (farqiga u dhexeeya irbadda mikroskoob iyo muunadda). Isticmaalka farsamadani waxay suurtogal ka dhigaysaa in la helo sawirro leh xalal sare. Waxa kale oo aad u isticmaali kartaa CO ama H2 cirbadda mikroskoob ee tan.
Image Image 2S waa sawir la helay iyadoo la isticmaalayo STM caaraddiisa lagu dahaadhay CO. Isbarbardhigga sawirada А, В и С waxay tusinaysaa in dhammaan walxaha atomiga lagu qeexay inay yihiin saddex geesood oo dhalaalaya oo isku xiga oo lagu hagayo laba jiho oo aan isu dhigmin (saddex xagal guduudan iyo jaale ah oo sawirada ku jira).
Sawirrada aaggan oo la ballaariyay2D) Xaqiiji in canaasiirtani ay heshiis la yihiin boron dopant nijaasta, oo qabsanaya laba qaybood oo graphene ah, sida ay muujinayaan qaab-dhismeedka sare.
Daahan CO ee cirbadda mikroskoobku waxay suurtagelisay in la muujiyo qaab-dhismeedka joomatari ee xaashida borophene (2E), taas oo aan suurtogal ahayn haddii irbaddu ay tahay mid caadi ah (birta) iyada oo aan lahayn daahan CO.
Sawirka #3
Samaynta wejiyada heterointerfaces ee u dhexeeya borophene iyo graphene (3A) waa in ay dhacdaa marka borophene ka korto dhinaca graphene ee ay hore ugu jireen boron.
Saynis yahanadu waxay xasuusinayaan in wejiyada heterointer-ka lateral ee ku salaysan graphene-hBN (graphene + boron nitride) ay leeyihiin isku dheelitirnaan, iyo heterojunctions oo ku saleysan biraha kala-guurka dichalcogenides waxay leeyihiin isku dheelitirnaan. Marka laga hadlayo graphene/borophene, xaaladdu xoogaa way ka duwan tahay - waxay leeyihiin isku ekaanshaha qaabdhismeed ugu yar marka loo eego joogtooyinka shabagga ah ama summaynta crystal. Si kastaba ha ahaatee, iyada oo ay taasi jirto, lateral graphene/borophene heterointerface waxay muujinaysaa ku dhowaad qummanaanta atomiga, oo leh jihooyinka boron (B-safka) ee la socda jihooyinka zigzag (ZZ) ee graphene (3A) Dhanka 3B sawirka la weyneeyey ee gobolka ZZ ee heterointerface-ka ayaa lagu muujiyey (khadadka buluuga ah waxay muujinayaan walxo isdhexgal ah oo u dhigma boron-carbon bonds covalent).
Maadaama borophene uu ku korayo heerkul hoose marka loo eego graphene, cidhifyada domainka graphene uma badna inay yeeshaan dhaqdhaqaaq sare marka la samaynayo heterointerface leh borophene. Sidaa darteed, interface-ka heterointerface-ka ku dhow ee saxda ah waxay u badan tahay inay ka dhalatay qaabaynyo kala duwan iyo sifooyin kala duwan oo curaarta boron ah. Sawirka tunneling spectroscopy spectra (3Siyo hagaajinta tunnel-ka kala duwan (3D) waxay tusinaysaa in kala-guurka elektarooniga ah ee graphene ilaa borophene uu ka dhaco masaafo ~ 5 Å ah oo aan lahayn astaamo muuqaal ah.
Sawirka 3E Waxaa la soo bandhigay saddex sawir oo tunneling spectroscopy spectra ah oo lagu qaaday saddexda xariiq ee 3D, kuwaas oo xaqiijinaya in kala-guurkan gaaban ee elektiroonigga ah uu yahay mid aan dareen u lahayn qaab-dhismeedyada gudaha ee gudaha oo la barbar dhigo kuwa isku xirka borophene-silver.
Sawirka #4
Graphene isdhexgalka* sidoo kale hore ayaa si weyn loo darsay, laakiin u beddelashada intercalants ee xaashida 2D ee runta ah waa dhif.
Isdhexgalka* - Ka mid noqoshada molecule ama koox ka mid ah molecules ee u dhexeeya molecules kale ama kooxaha molecules.
Radiuska atomiga yar ee boron iyo isdhexgalka daciifka ah ee u dhexeeya graphene iyo Ag(111) waxay soo jeedinayaan suurtogalnimada isdhexgalka graphene iyo boron. Sawirka 4A caddaynta ma aha oo kaliya isdhexgalka boron, laakiin sidoo kale samaynta borophene-graphene heterostructures toosan, gaar ahaan qaybaha saddex-geesoodka ah ee ku wareegsan graphene. Shabagga malabka ee lagu arkay qaybtan saddexagalka ah ayaa xaqiijinaysa joogitaanka graphene. Si kastaba ha ahaatee, graphenekan ayaa muujinaya cufnaanta hoose ee gobolada -50 mV marka la barbar dhigo graphene ku wareegsan (4B). Marka la barbar dhigo graphene si toos ah Ag(111), ma jiraan wax caddaynaya cufnaanta sare ee dawladaha hoose ee spectrum dI/dV (4C, qalooca buluuga ah), oo u dhiganta Ag(111) gobolka dusha sare, waa caddaynta ugu horreysa ee isdhexgalka boron.
Sidoo kale, sida la filayo isdhexgalka qayb ahaan, xargaha graphene wuxuu ahaanayaa mid joogto ah inta lagu jiro isdhexgalka dambe ee u dhexeeya graphene iyo gobolka saddex xagal (4D - waxay u dhigantaa meel leydi ah oo saaran 4A, ku wareegsan xariiq dhibco cas). Sawir la isticmaalayo CO ee cirbadda mikroskoobku waxa kale oo uu xaqiijiyay jiritaanka wasakhda beddelka boron4E - waxay u dhigantaa meel leydi ah oo saaran 4A, ku wareegsan xariiq dhibco jaale ah).
Cirbadaha mikroskoob ee aan lahayn dahaarka ayaa sidoo kale la isticmaalay intii lagu jiray falanqaynta. Xaaladdan oo kale, calaamadaha canaasirta toosan ee hal-geesoodka ah oo leh wakhti wakhti ah 5 Å ayaa lagu muujiyay qaybaha garaafka isku-dhafan (4F и 4G). Qaab-dhismeedyadan hal-geesoodka ah waxay u egyihiin safafka boron ee qaabka borophene. Marka lagu daro jaangooyooyinka dhibcaha u dhigma graphene, Fourier-ka ayaa u beddela sawirka 4G soo bandhigaya labo dhibcood oo orthogonal ah oo u dhiganta 3 Å x 5 Å shabag leydi ah (4H), kaas oo si fiican ula heshiiyey qaabka borophene. Intaa waxaa dheer, jihaynta saddex-geesoodka ah ee la arkay ee isku-dhafka walxaha toosan (1E) si fiican ugu raacsan yahay isla qaab-dhismeedka ugu badan ee lagu arkay xaashida borophene.
Dhammaan indho-indhayntu waxay si xooggan u soo jeedinayaan isdhexgalka graphene by borophene ee u dhow cidhifyada Ag, taas oo keentay in la sameeyo borophene-graphene heterostructures toosan, taas oo si faa'iido leh loo ogaan karo iyada oo la kordhinayo daboolka hore ee graphene.
4I waa qaab-dhismeedka qaab-dhismeed toosan oo saaran 4H, halkaas oo jihada safka boron (falaarta casaanka) ay si dhow ula socoto jihada zigzag ee graphene ( falaarta madow), sidaas darteed sameynta qaab-dhismeed toosan oo wareeg ah.
Si aad u hesho aqoon faahfaahsan oo ku saabsan nuxurka daraasadda, waxaan ku talinayaa in la eego и isaga.
Epilogue
Daraasadani waxay muujisay in borophene uu awood u leeyahay inuu sameeyo qaab-dhismeedka heterostructures lateral iyo toosan oo leh graphene. Nidaamyada noocan oo kale ah waxaa loo isticmaali karaa horumarinta noocyada cusub ee walxaha laba-geesoodka ah ee loo isticmaalo nanotechnology, qalabka elektarooniga ah ee dabacsan oo xiran, iyo sidoo kale noocyada cusub ee semiconductors.
Cilmi-baadhayaashu laftoodu waxay aaminsan yihiin in korriintoodu ay noqon karto riix xoog leh oo hore loogu qaado tignoolajiyada elektiroonigga ah. Si kastaba ha ahaatee, weli way adag tahay in la sheego si hubaal ah in hadalladoodu noqon doonaan nebi. Waqtigan xaadirka ah, waxaa weli jira wax badan oo u baahan in la baaro, la fahmo oo la ikhtiraaco si fikradaha mala-awaalka sayniska ee buuxiya maskaxda saynisyahanadu ay u noqdaan xaqiiqo buuxda.
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Source: www.habr.com