Tinokutendai nekunyoresa nePhysics World Kana muchida kuchinja ruzivo rwenyu chero nguva, ndapota shanyirai My account
Mafirimu eGraphite anogona kudzivirira michina yemagetsi kubva kumwaranzi yemagetsi (EM), asi matekiniki aripo pari zvino ekugadzira anotora maawa akati wandei uye anoda tembiricha yekupisa inosvika 3000 °C. Chikwata chevaongorori vanobva kuShenyang National Laboratory for Materials Science paChinese Academy of Sciences ikozvino charatidza imwe nzira yekugadzira mafirimu eGraphite emhando yepamusoro mumasekonzi mashoma nekudzima zvidimbu zvinopisa zve nickel foil mu ethanol. Mwero wekukura kwemafirimu aya wakakwira kupfuura nzira dziripo, uye simba remagetsi remafirimu aya rakaenzana neremafirimu akagadzirwa achishandisa chemical vapour deposition (CVD).
Midziyo yese yemagetsi inogadzira mwaranzi yeEM. Sezvo michina ichiramba ichiita diki uye ichishanda pamafrequency akakwira, mukana wekukanganiswa kwemagetsi (EMI) unowedzera, uye unogona kukanganisa mashandiro emudziyo pamwe neaya emagetsi ari pedyo.
Graphite, iyo allotrope yekabhoni yakavakwa kubva muzvikamu zvegraphene zvakabatanidzwa pamwe chete nemauto evan der Waals, ine huwandu hwakawanda hwesimba remagetsi, rekupisa uye remakanika rinoita kuti ive nhoo inoshanda kubva kuEMI. Zvisinei, inofanirwa kunge iri muchimiro chefirimu rakatetepa kuti ive nemagetsi akakwira, izvo zvakakosha pakushandiswa kweEMI nekuti zvinoreva kuti chinhu chacho chinogona kuratidza uye kunyudza mafungu eEM sezvaanobatana nemagetsi ari mukati mayo.
Parizvino, nzira huru dzekugadzira graphite film dzinosanganisira high-temperature pyrolysis ye aromatic polymers kana kuisa graphene (GO) oxide kana graphene nanosheets layer by layer. Maitiro ese ari maviri anoda tembiricha yepamusoro inosvika 3000 °C uye nguva dzekugadzirisa dzeawa imwe chete. MuCVD, tembiricha inodiwa yakaderera (pakati pe700 kusvika 1300 °C), asi zvinotora maawa mashoma kugadzira mafirimu ane ukobvu hwe nanometer, kunyangwe mu vacuum.
Chikwata chinotungamirwa naWencai Ren chagadzira firimu repamusoro-soro regraphite rine ukobvu hwemakumi emakumi emamamita mukati memasekonzi mashoma nekupisa nickel foil kusvika 1200 °C mumhepo yeargon uye nekukurumidza kunyudza iyi foil mu ethanol pa0 °C. Maatomu ekabhoni anogadzirwa kubva mukuora kweethanol anopararira uye anonyungudika mu nickel nekuda kwekunyungudika kwakanyanya kwesimbi (0.4 wt% pa1200 °C). Nekuti kunyungudika uku kwekabhoni kunoderera zvakanyanya pakupisa kwakaderera, maatomu ekabhoni anozoparadzanisa uye anodonha kubva pamusoro pe nickel panguva yekudzima, zvichigadzira firimu gobvu regraphite. Vaongorori vanotaura kuti basa rakanaka re catalytic re nickel rinobatsirawo kuumbwa kwe graphite ine crystalline yakawanda.
Vachishandisa musanganiswa we high-resolution transmission microscopy, X-ray diffraction uye Raman spectroscopy, Ren nevamwe vake vakaona kuti graphite yavakagadzira yaive yakajeka munzvimbo dzakakura, yakarukwa zvakanaka uye isina zvikanganiso zvinoonekwa. Kufambiswa kwemaerekitironi kwefirimu kwaive kwakakwira kusvika 2.6 x 105 S/m, zvakafanana nemafirimu akakura neCVD kana matekiniki ekupisa kwakanyanya uye kudzvanywa kwemafirimu eGO/graphene.
Kuti vaedze kuti zvinhu izvi zvinogona sei kudzivirira mwaranzi yeEM, timu iyi yakaendesa mafirimu ane nzvimbo yepamusoro ye600 mm2 kuzvinhu zvakagadzirwa nepolyethylene terephthalate (PET). Vakazoyera kushanda kweEMI shielding efficiency (SE) muX-band frequency range, pakati pe8.2 ne12.4 GHz. Vakawana EMI SE inodarika 14.92 dB yefirimu ine ukobvu hwe77 nm. Kukosha uku kunowedzera kusvika kupfuura 20 dB (kukosha kunodiwa pakushandiswa kwekutengeserana) muX-band yese pavakaunganidza mamwe mafirimu pamwe chete. Zvechokwadi, firimu rine zvidimbu zvishanu zvemafirimu egraphite akaunganidzwa (anenge 385 nm ukobvu muhuwandu hwese) rine EMI SE inodarika 28 dB, zvinoreva kuti zvinhu izvi zvinogona kudzivirira 99.84% yemwaranzi yechiitiko. Zvose, timu iyi yakayera EMI shielding ye481,000 dB/cm2/g muX-band, ichipfuura zvese zvakagadzirwa kare.
Vaongorori vanoti neruzivo rwavo rwese, girafiti yavo ndiyo yakatetepa kupfuura dzimwe dzese dzinonzi dzinodzivirira, ine mashandiro ekudzivirira eEMI anogona kugutsa zvinodiwa pakushandiswa kwekutengeserana. Hunhu hwayo hwemakanika hwakanakawo. Simba rekupwanyika kwechinhu ichi rinosvika 110 MPa (rinotorwa kubva mumakombama ekumanikidzwa kwezvinhu zvakaiswa pakutsigira kwepolycarbonate) rakakwirira kupfuura remafirimu egirafiti akakurirwa nedzimwe nzira. Firimu iri rinochinjikawo, uye rinogona kukotama ka1000 neredhiyo yekukotama ye5 mm pasina kurasikirwa nehunhu hwayo hwekudzivirira hweEMI. Rinochinjikawo pakupisa kusvika 550 °C. Chikwata ichi chinotenda kuti hunhu uhwu nezvimwe zvinoreva kuti hunogona kushandiswa sechinhu chekudzivirira cheEMI chakatetepa, chakareruka, chinochinjika uye chinoshanda chekushandisa munzvimbo dzakawanda, kusanganisira aerospace pamwe nemagetsi ne optoelectronics.
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Nguva yekutumira: Chivabvu-07-2020