Ndatenda nekunyoresa nePhysics World Kana iwe uchida kushandura ruzivo rwako chero nguva, ndapota shanyira My account
Mafirimu egraphite anogona kudzivirira michina yemagetsi kubva kumagetsi emagetsi (EM) mwaranzi, asi matekiniki aripo ekuagadzira anotora maawa akati wandei uye anoda kugadzirisa tembiricha inosvika 3000 ° C. Chikwata chevaongorori kubva kuShenyang National Laboratory for Materials Science paChinese Academy of Sciences chave kuratidza imwe nzira yekugadzira mafirimu emhando yepamusoro-soro mumasekonzi mashoma nekudzima zvidimbu zvinopisa zve nickel foil mu ethanol. Mwero wekukura kwemafirimu aya unodarika maodha maviri ehukuru hwepamusoro pane nzira dziripo, uye mashandiro emagetsi emafirimu uye simba remuchina zviri padanho remafirimu akagadzirwa pachishandiswa kemikari vapor deposition (CVD).
Zvese zvigadzirwa zvemagetsi zvinogadzira imwe EM mwaranzi. Sezvo michina inoramba ichiva diki uye kushanda pakakwirira uye yakakwirira frequency, mukana wekukanganiswa kwemagetsi (EMI) unokura, uye unogona kukanganisa kuita kwechishandiso pamwe neiyo yemagetsi ari pedyo masisitimu.
Graphite, allotrope yekabhoni yakavakwa kubva kune akaturikidzana egraphene akabatwa pamwechete nevan der Waals mauto, ane akati wandei anoshamisa emagetsi, ekupisa uye emuchina zvivakwa zvinoita kuti ive nhovo inoshanda pakurwisa EMI. Nekudaro, inofanirwa kunge iri muchimiro chefirimu rakatetepa kwazvo kuti ive nemhando yepamusoro yemagetsi, izvo zvakakosha kune inoshanda EMI application nekuti zvinoreva kuti izvo zvinhu zvinogona kuratidza uye kutora mafungu eEM pavanenge vachidyidzana nevatakuri vechaji mukati. it.
Parizvino, nzira huru dzekugadzira firimu regraphite dzinosanganisira kana yakakwirira-tembiricha pyrolysis yemapolymer anonhuhwirira kana kurongedza graphene (GO) oxide kana graphene nanosheets layer by layer. Maitiro ese ari maviri anoda tembiricha yepamusoro inosvika 3000 °C uye nguva dzekugadzirisa dzeawa. MuCVD, tembiricha inodiwa yakadzikira (pakati pe700 kusvika 1300 ° C), asi zvinotora maawa mashoma kugadzira nanometre-makobvu mafirimu, kunyange muvacuum.
Chikwata chinotungamirwa naWencai Ren chagadzira firimu remhando yepamusoro makumi ema nanometers mukati memasekonzi mashoma nekudziya nickel foil kusvika 1200 °C mumhepo yeArgon uye nekukasira kunyudza foil iyi mu ethanol pa 0 °C. Kabhoni maatomu anogadzirwa kubva pakuora ethanol anopararira uye kunyungudika kuita nickel nekuda kwesimbi yakakwira kabhoni solubility (0.4 wt% pa1200 °C). Nekuti kunyungudika kwekabhoni uku kunodzikira zvakanyanya pakudziya kwakaderera, maatomu ekabhoni anobva apatsanura uye nekunaya kubva pane nickel pamusoro panguva yekudzima, achigadzira gobvu regirafu firimu. Vatsvagiri vanoshuma kuti yakanakisa catalytic chiitiko chenickel inobatsirawo kuumbwa kweiyo yakanyanya crystalline graphite.
Vachishandisa musanganiswa wepamusoro-resolution transmission microscopy, X-ray diffraction uye Raman spectroscopy, Ren nevamwe vaaishanda navo vakawana kuti girafu ravakagadzira rakanga rakanyanya crystalline panzvimbo hombe, rakaturikidzana uye rakanga risina hurema hunooneka. Maelectron conductivity emufirimu akanga akakwirira se 2.6 x 105 S/m, akafanana nemafirimu akakura neCVD kana maitiro ekupisa kwepamusoro uye kudzvanya kweGO/graphene mafirimu.
Kuti uedze kuti zvinhu izvi zvingavharisa sei EM mwaranzi, timu yakaendesa mafirimu ane nzvimbo ye600 mm2 pazvikamu zvakagadzirwa nepolyethylene terephthalate (PET). Vakabva vayera firimu reEMI kudzivirira kushanda zvakanaka (SE) muX-band frequency renji, pakati pe8.2 ne12.4 GHz. Vakawana EMI SE yeanopfuura 14.92 dB yefirimu rinenge 77 nm gobvu. Ukoshi uhwu hunowedzera kupfuura 20 dB (iyo shoma kukosha inodiwa kune zvekutengesa zvikumbiro) muX-bhendi yese pavakarongedza mamwe mafirimu pamwechete. Chokwadi, firimu rine zvimedu zvishanu zvemafirimu egraphite akaturikidzana (akatenderedza 385 nm mukobvu pakazara) ane EMI SE inotenderedza 28 dB, zvinoreva kuti zvinhu zvinogona kuvhara 99.84% yechiitiko mwaranzi. Pakazere, timu yakayera EMI kudzivirira kwe481,000 dB/cm2/g mhiri kweX-bhendi, ichipfuura zvese zvakambotaurwa zvekugadzira zvinhu.
Vatsvagiri vacho vanoti sekuziva kwavo, firimu ravo remagraphite ndiro rakatetepa pakati pezvakarehwa zvekudzivirira zvinhu, zvine EMI shielding performance iyo inogona kugutsa chinodiwa chekushambadzira maapplication. Iwo ma mechanical properties anofarirawo. Simba rekutsemuka kwechinhu chinoda kusvika 110 MPa (yakabviswa kubva mukushushikana-kudzvanya macurves echinhu chakaiswa papolycarbonate rutsigiro) yakakwira kupfuura iyo yemafirimu emagraphite anokura nedzimwe nzira. Iyo firimu inochinjika, zvakare, uye inogona kupetwa ka1000 neinokotama radius ye5 mm pasina kurasikirwa neEMI inodzivirira zvivakwa. Iyo zvakare yakagadzikana nekushisa kusvika ku550 ° C. Chikwata ichi chinotenda kuti izvi nezvimwe zvivakwa zvinoreva kuti zvinogona kushandiswa seyeultrathin, isingaremi, inochinjika uye inoshanda EMI kudzivirira zvinhu zvekushandisa munzvimbo dzakawanda, kusanganisira aerospace pamwe nemagetsi uye optoelectronics.
Verenga iyo inonyanya kukosha uye inonakidza kufambira mberi mune zvekushandisa sainzi mune ino nyowani yakavhurika yekuwana magazini.
Physics World inomiririra chikamu chakakosha cheIOP Publishing's mission yekutaurirana tsvakiridzo yepasirese uye hunyanzvi kune vateereri vakanyanya. Iyo webhusaiti inoumba chikamu cheiyo Physics World portfolio, muunganidzwa wepamhepo, dijitari uye anodhinda ruzivo masevhisi enharaunda yepasi rose yesainzi.
Nguva yekutumira: May-07-2020