“Mgbanwe bụ isi ihe na-ekpughe ihe omimi nke evolushọn. Ụzọ mmepe site na organism kachasị mfe ruo n'ụdị ndu ndu na-adịru ọtụtụ puku afọ. Ma otu narị puku afọ ọ bụla, a na-enwe ọganihu dị nkọ na evolushọn" (Charles Xavier, X-Men, 2000). Ọ bụrụ na anyị atụfuo ihe niile gbasara akụkọ ifo sayensị dị na ihe nkiri na ihe nkiri, mgbe ahụ okwu Prọfesọ X bụ eziokwu. Mmepe nke ihe na-aga n'ihu n'ọtụtụ oge, ma mgbe ụfọdụ enwere jumps nke nwere mmetụta dị ukwuu na usoro dum. Nke a na-emetụta ọ bụghị nanị na evolushọn nke ụdị, kamakwa na evolushọn nke nkà na ụzụ, bụ isi ọkwọ ụgbọala nke ndị mmadụ, ha nnyocha na mepụtara. Taa, anyị ga-amata ọmụmụ ihe na, dị ka ndị dere ya si kwuo, bụ ezigbo mmụba evolushọn na nanotechnology. Kedu ka ndị ọkà mmụta sayensị sitere na Mahadum Northwwest (USA) siri nwee ike ịmepụta heterostructure ọhụrụ nwere akụkụ abụọ, gịnị kpatara eji họrọ graphene na borophene dị ka ihe ndabere, oleekwa ihe ndị dị otú ahụ nwere ike inwe? Akụkọ nke otu nyocha ga-agwa anyị gbasara nke a. Gaa.
Ntọala nyocha
Anyị anụla okwu ahụ bụ "graphene" ọtụtụ oge; ọ bụ mgbanwe akụkụ abụọ nke carbon, nke nwere oyi akwa carbon carbon 1 atom. Mana "borofen" dị oke ụkọ. Okwu a na-ezo aka na kristal nwere akụkụ abụọ nwere naanị atom boron (B). Enwere ike ibu amụma banyere ịdị adị nke borophene n'etiti afọ 90, mana na omume, enwetara usoro a naanị site na 2015.
Nhazi atomic nke borophene nwere triangular na hexagonal element na bụ ihe si na mmekọrịta dị n'etiti etiti abụọ na ọtụtụ etiti dị n'ime ụgbọ elu, bụ nke a na-ahụkarị maka ihe ndị na-enweghị electron, nke gụnyere boron.
*Site na njikọ nke etiti abụọ na nke multicenter anyị pụtara njikọ kemịkalụ - mmekọrịta nke atọm nke na-akọwa nkwụsi ike nke molecule ma ọ bụ kristal dị ka otu nhazi. Dịka ọmụmaatụ, njikọ elektrọn abụọ dị n'etiti etiti na-eme mgbe 2 atom na-ekerịta 2 electrons, na njikọ elektrọn nke etiti etiti atọ na-eme mgbe 2 atọ na 3 electrons, wdg.
Site n'echiche anụ ahụ, borophene nwere ike ịdị ike ma gbanwee karịa graphene. Ekwenyere na ihe owuwu borophene nwere ike ịbụ ihe nkwado dị irè maka batrị, ebe borophene nwere ikike dị elu nke ọma na ihe omume eletrọnịkị pụrụ iche na akụrụngwa njem ion. Otú ọ dị, n'oge a bụ nanị tiori.
Ịbụ elementrị trivalent*, boron nwere opekata mpe iri allotropes*. N'ụdị akụkụ abụọ, yiri ya polymorphism* a na-ahụkwa.
Ihe atọ dị iche iche* ike nke na-akpụ atọ covalent agbụ, valency nke bụ atọ.
Allotropy* - mgbe enwere ike igosi otu ihe kemịkalụ n'ụdị ihe abụọ ma ọ bụ karịa dị mfe. Dịka ọmụmaatụ, carbon - diamond, graphene, graphite, carbon nanotubes, wdg.
Polymorphism* - ike nke ihe dị n'ụdị kristal dị iche iche (mgbanwe polymorphic). N'ihe gbasara ihe ndị dị mfe, okwu a na-ejikọta ya na allotropy.
Nyere polymorphism a sara mbara, a na-atụ aro na borophene nwere ike ịbụ ezigbo onye ndoro-ndoro maka ịmepụta heterostructures akụkụ abụọ ọhụrụ, ebe ọ bụ na nhazi boron bonding dị iche iche kwesịrị ime ka ihe kwekọrọ na lattice chọrọ. N'ụzọ dị mwute, a na-amụbu okwu a naanị na ọkwa nke usoro n'ihi ihe isi ike na njikọ.
Maka ihe 2D a na-ahụkarị nke enwetara site na kristal nwere nnukwu oyi akwa, enwere ike imepụta heterostructures kwụ ọtọ site na iji nchikota igwe. N'aka nke ọzọ, akụkụ abụọ nke akụkụ heterostructures na-adabere na njikọ nke ala. Usoro heterostructures dị n'akụkụ atomically nwere ikike dị ukwuu n'ịgwọ nsogbu njikwa ọrụ heterojunction, agbanyeghị, n'ihi njikọta nke covalent, dakọtara lattice na-ezughị oke na-ebutekarị oghere na enweghị nsogbu. Ya mere, enwere ike, mana enwerekwa nsogbu na ịghọta ya.
N'ime ọrụ a, ndị nchọpụta ahụ jisiri ike jikọta borophene na graphene n'ime otu heterostructure akụkụ abụọ. N'agbanyeghị kristal lattice mismatch na symmetry dị n'etiti borophene na graphene, usoro ntinye nke carbon na boron na ntinye nke Ag(111) n'okpuru ultra-high vacuum (UHV) na-ebute ihe fọrọ nke nta ka ọ bụrụ akụkụ dị n'akụkụ heterointerface atomically nwere nhazi nke lattice buru amụma, yana vetikal heterointerfaces. .
Nkwadebe ọmụmụ ihe
Tupu ịmụ banyere heterostructure, a ga-emepụta ya. A na-eme uto nke graphene na borophene n'ime ụlọ oghere dị oke elu nke nwere nrụgide nke 1x10-10 millibars.
A na-ehicha otu mkpụrụ kristal Ag (111) site n'usoro nke Ar + sputtering ugboro ugboro (1 x 10-5 millibar, 800 eV, 30 nkeji) na annealing (550 Celsius C, 45 nkeji) iji nweta atomically dị ọcha na larịị Ag 111) elu.
A na-etolite Graphene site na ikuku ọkụ eletrik nke mkpanaka graphite dị ọcha (99,997%) nwere dayameta nke 2.0 mm na ntinye Ag (750) na-ekpo ọkụ ruo 111 Celsius C na ọkụ ọkụ nke ~ 1.6 A na voltaji na-agba ọsọ nke ~ 2 kV , nke na-enye ikuku ikuku nke ~ 70 mA na carbon flux ~ 40 nA. Nrụgide dị n'ime ụlọ ahụ bụ 1 x 10-9 millibars.
A na-etolite Borophene site na evaporation eletrọn nke dị ọcha (99,9999%) boron mkpanaka n'elu submonolayer graphene na Ag (400) na-ekpo ọkụ ruo 500-111 Celsius. Igwe filament dị ugbu a bụ ~ 1.5 A na voltaji na-eme ngwa ngwa bụ 1.75 kV, nke na-enye ikuku ugbu a nke ~ 34 mA na flux boron nke ~ 10 nA. Nrụgide dị n'ime ụlọ n'oge uto nke borophene bụ ihe dịka 2 x 10-10 millibars.
Nsonaazụ nyocha
Foto #1
Na onyonyo a 1A gosiri STM* foto nke graphene toro eto, ebe a na-ahụta ngalaba graphene kacha mma site na iji maapụ dI/dV (1B), ebe I и V bụ tunneling ugbu a na nlegharị anya sample, na d - njupụta.
STM* - nyocha microscope tunneling.
dI/dV Maapụ ihe atụ nyere anyị ohere ịhụ njupụta mpaghara dị elu nke steeti graphene ma e jiri ya tụnyere ag (111). Dị ka ọmụmụ gara aga, ala ala Ag (111) nwere njirimara nzọụkwụ, gbanwere ike dị mma site na dI/dV ụdịdị dị iche iche nke graphene (1), nke na-akọwa njupụta mpaghara dị elu nke steeti graphene on 1B na 0.3eV.
Na onyonyo a 1D anyị nwere ike ịhụ Ọdịdị nke otu-oyi akwa graphene, ebe ebuanu lattice na moiré superstructure*.
Nhazi kacha mma* - akụkụ nke nhazi nke ogige kristal nke na-emegharị n'otu oge ma si otú a na-emepụta ihe ọhụrụ na oge mgbanwe dị iche iche.
Moire* - superposition nke abụọ oge ntupu ụkpụrụ n'elu onye ọ bụla ọzọ.
Na okpomọkụ dị ala, uto na-eduga n'ịmepụta ngalaba dendritic na ntụpọ graphene. N'ihi mmekọrịta adịghị ike n'etiti graphene na ihe dị n'okpuru, nhazigharị nke graphene n'ihe gbasara Ag(111) abụghị ihe pụrụ iche.
Mgbe egosiri boron, nyochaa microscopy tunneling (1E) gosipụtara ọnụnọ nke ngwakọta nke ngalaba borophene na graphene. A na-ahụkwa na foto a bụ mpaghara dị n'ime graphene, bụ nke e mechara chọpụta dị ka graphene jikọtara ya na borophene (nke egosiri na foto a). Gr/B). A na-ahụkwa ihe ndị dị n'ahịrị n'akụkụ atọ ma kewaa ya n'akụkụ 120º na mpaghara a (akụ na-acha odo odo).
Foto #2
Foto na 2Aka 1E, gosi na mpụta nke ịda mbà n'obi gbara ọchịchịrị na graphene mgbe ọ gbasasịrị boron.
Iji nyochaa usoro ndị a nke ọma wee chọpụta ebe ha si, e sere foto ọzọ nke otu mpaghara, mana iji maapụ |dlnI/dz| (2B), ebe I - ọwara ugbu a, d bụ njupụta, na z - nkewa nke nyocha-sample (ohere dị n'etiti agịga microscope na ihe nlele). Ojiji nke usoro a na-eme ka o kwe omume ịnweta ihe oyiyi nwere oke oghere dị elu. Ị nwekwara ike iji CO ma ọ bụ H2 na agịga microscope maka nke a.
Image Image 2 bụ onyonyo enwetara site na iji STM nke ejiri CO kpuchie ọnụ ya. Ntụnyere onyonyo А, В и С na-egosi na a kọwapụtara ihe atọmịk niile dị ka hexagon atọ na-egbuke egbuke na-eduzi n'akụkụ abụọ na-enweghị isi (triangles uhie na odo na foto).
Foto ndị mepere emepe nke mpaghara a (2D) kwadoro na ihe ndị a na-ekwenye na boron dopant adịghị ọcha, na-eburu graphene sublatices abụọ, dị ka egosipụtara n'elu ụlọ.
Mkpuchi CO nke agịga microscope mere ka o kwe omume ikpughe nhazi geometric nke mpempe akwụkwọ borophene (2E), nke na-agaghị ekwe omume ma ọ bụrụ na agịga ahụ bụ ọkọlọtọ (metal) na-enweghị mkpuchi CO.
Foto #3
Nhazi nke ihu heterointerface n'etiti borophene na graphene (3A) kwesịrị ime mgbe borophene na-eto n'akụkụ ngalaba graphene nke nwere boron.
Ndị ọkà mmụta sayensị na-echetara na mpụta heterointerfaces dabere na graphene-hBN (graphene + boron nitride) nwere nkwụsi ike nke lattice, na heterojunctions dabere na metal dichalcogenides mgbanwe nwere nkwụsi ike. N'ihe banyere graphene / borophene, ọnọdụ ahụ dịtụ iche - ha nwere obere myirịta nhazi n'usoro nke lattice constants ma ọ bụ kristal symmetry. Otú ọ dị, n'agbanyeghị nke a, akụkụ graphene / borophene heterointerface na-egosipụta ihe fọrọ nke nta ka ọ bụrụ nkwekọ atọm zuru oke, na ntụzịaka boron (B-ahịrị) kwekọrọ na ntụziaka zigzag (ZZ) nke graphene (3A). Gbanye 3B a na-egosipụta nnukwu ihe oyiyi nke mpaghara ZZ nke heterointerface (ahịrị na-acha anụnụ anụnụ na-egosi ihe dị n'etiti ihu na-ejikọta na boron-carbon covalent bonds).
Ebe ọ bụ na borophene na-eto na okpomọkụ dị ala ma e jiri ya tụnyere graphene, akụkụ nke ngalaba graphene enweghị ike inwe nnukwu njem mgbe ọ na-emepụta heterointerface na borophene. Ya mere, ihe fọrọ nke nta ka ọ bụrụ nke ziri ezi heterointerface nwere ike ịbụ n'ihi nhazi dị iche iche na njirimara nke njikọ boron multisite. Na-enyocha ihe nkiri spectroscopy tunneling (3) na ọdịiche ọwara conductivity (3D) na-egosi na ntụgharị eletrọnịkị site na graphene na borophene na-eme n'ebe dị anya nke ~ 5 Å na-enweghị ihe ngosi ngosi a na-ahụ anya.
Na onyonyo a 3E Egosipụtara bụ ihe nleba anya nlegharị anya nyocha atọ a na-ewere n'akụkụ ahịrị atọ a gbajiri agbaji na 3D, nke na-akwado na ngbanwe eletrọnịkị a dị mkpụmkpụ enweghị mmetụta n'ọdịdị ihu dị n'ime mpaghara ma yie nke ahụ na oghere borophene-ọlaọcha.
Foto #4
Graphene njikọta* A mụọlakwa ya nke ọma na mbụ, mana ntụgharị nke intercalants ka ọ bụrụ ezigbo mpempe akwụkwọ 2D dị ụkọ.
Mmekọrịta* - mweghachi nke molekul ma ọ bụ otu ụmụ irighiri ihe dị n'etiti ụmụ irighiri ihe ndị ọzọ ma ọ bụ otu ụmụ irighiri ihe.
Obere radius atomic nke boron na mmekọrịta adịghị ike n'etiti graphene na Ag(111) na-atụ aro ka enwere ike ịmekọrịta graphene na boron. Na onyonyo a 4A A na-egosikwa ihe akaebe ọ bụghị naanị nke njikọta boron, kamakwa nke nguzobe nke heterostructures borophene-graphene kwụ ọtọ, ọkachasị ngalaba triangular nke graphene gbara ya gburugburu. Ihe mkpuchi mmanụ aṅụ a hụrụ na mpaghara triangular a na-akwado ọnụnọ nke graphene. Agbanyeghị, graphene a na-egosipụta njupụta mpaghara dị ala na -50 meV ma e jiri ya tụnyere graphene gbara ya gburugburu (4B). E jiri ya tụnyere graphene ozugbo na Ag(111), ọ nweghị ihe akaebe nke nnukwu njupụta mpaghara nke steeti na ụdịdị dị iche iche. dI/dV (4C, blue curve), kwekọrọ na ala ala Ag(111), bụ ihe akaebe mbụ nke boron intercalation.
Ọzọkwa, dị ka a na-atụ anya maka njikọta akụkụ, graphene lattice na-anọgide na-aga n'ihu n'akụkụ akụkụ dị n'etiti graphene na mpaghara triangular (4D - kwekọrọ na mpaghara akụkụ anọ na 4A, gbara ya gburugburu n'ahịrị nwere ntụpọ uhie). Onyonyo na-eji CO na agịga microscope gosikwara na ọnụnọ boron adịghị arụ ọrụ (4E - kwekọrọ na mpaghara akụkụ anọ na 4A, gbara ya gburugburu n'ahịrị nwere ntụpọ edo edo).
A na-ejikwa agịga microscope na-enweghị mkpuchi ọ bụla n'oge nyocha. N'okwu a, a na-ekpughe ihe ịrịba ama nke ihe ndị dị n'otu akụkụ nke nwere oge nke 5 Å na mpaghara graphene na-ejikọta ọnụ (4F и 4G). Ihe owuwu ndị a nwere otu akụkụ yiri ahịrị boron na ụdị borophene. Na mgbakwunye na setịpụrụ isi ihe kwekọrọ na graphene, Fourier na-agbanwe ihe oyiyi ahụ n'ime 4G na-egosiputa otu ụzọ orthogonal kwekọrọ na lattice akụkụ anọ 3 Å x 5 Å (4H), nke dị na nkwekọrịta magburu onwe ya na ihe nlereanya borophene. Tụkwasị na nke ahụ, ntụzịaka ugboro atọ a hụrụ n'usoro ihe nke linear (1E) kwekọrịtara nke ọma na otu usoro a na-ahụkarị maka akwụkwọ borophene.
Nlebanya ndị a niile na-akwadosi ike na njikọta nke graphene site na borophene dị nso na nsọtụ Ag, nke na-eduga na nguzobe nke borophene-graphene heterostructures kwụ ọtọ, nke enwere ike nweta nke ọma site na ịbawanye mkpuchi mbụ nke graphene.
4I bụ ihe atụ schematic nke heterostructure kwụ ọtọ na 4H, ebe ntụzịaka nke ahịrị boron (akụ pink) na-ejikọta ya na zigzag ntụziaka nke graphene (akụ ojii), si otú a na-emepụta heterostructure kwụ ọtọ na-agbanwe agbanwe.
Maka ịmatakwu nke ọma na nuances nke ọmụmụ ihe, ana m akwado ile anya и nye ya.
Epilogue
Ọmụmụ ihe a gosiri na borophene nwere ike iji graphene mepụta akụkụ mpụta na vetikal heterostructures. Enwere ike iji usoro dị otú ahụ mee ihe n'ịzụlite ụdị ọhụrụ nke akụkụ abụọ nke ihe eji eme ihe na nanotechnology, ngwá electronic na-agbanwe na wearable, yana ụdị semiconductor ọhụrụ.
Ndị na-eme nchọpụta n'onwe ha kwenyere na mmepe ha nwere ike ịbụ nnukwu nkwalite maka teknụzụ ndị metụtara eletrọnịkị. Otú ọ dị, ọ ka na-esi ike ikwu n’ezie na okwu ha ga-abụ amụma. N'oge a, a ka nwere ọtụtụ ihe a ga-enyocha, ghọta na chepụta ka echiche sayensị ndị ahụ jupụtara n'uche ndị ọkà mmụta sayensị ghọọ eziokwu zuru oke.
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