23. He do phd huynh quang va phd truyen qua
23.1He do phd huynh quang
Cac phd huynh quang cua tit ci cac mang Zn^Cdi^^S khdng pha tap va cd pha tap da dupe do bing he huynh quang. Sa đ khdi cua he dupe md ta tren hinh 19.
Ngudn anh sang kfch thfch la den thiiy ngan cao ap Model 66032, cd cdng suit
200W. Den dupe dat trong hop bao vẹ He thdng dieu chinh cac gUOng, thiu kfnh
chiy lien tuc quanh bp Ipc sic cua den. Den thiiy ngan dupe nudi bang ngudn dn ap chuyen dung Model 68810, cdng suit 200 - 500W.
Hinh 19. Sa do khdi ciia he do huynh quang
N - Ngudn anh sing kfch thfch MDS - May don s^c TKl, TK2 - Thiu kfnh hoi tu
L - Lpc sic M - Miu do
CR - Binh dieu lanh (cryostat) TL - Tay lanh
DB - Bd di^u bien
NQD - Ong nhan quang dien Pd - Photodiot
D - Den 6V
THC - B6 phit tfn hieu chuin LA - Lock in Amplifier TG - Tu ghi
Td hpp kfnh lpc gdm lpc sic YOC6 va hdp lpc chiia dung dich CUSO4 bao hdạ
Td hpp kfnh Ipc chi cho qua anh sang kfch thfch vdi budc sdng X = 365 nm.
M i u do dupe dat tren gia cd thi quay, dich chuyin dupe trong khdng gian ba chiSụ Khi do d nhiet dp thap, mau dupe gin trong cryostat, tren tay lanh. Cd hai loai cryostat da dupe sir dung. Mdt loai bang thuy tinh pyrex hut chan khdng 10"^ mmHg. Trong cryostat nay, miu cd the nhiing true tidp vao nita long. Mot loai cryostat khac Iam bang thep khdng ri, cd ciia d l hiit chin khdng bang bam chan
khdng trong sudt qua trinh dọ Cufa sd dl cho anh sang kich thfch vao dat chech mdt gdc 45° so vdi ciia sd cho anh sang huynh quang ra khdi cryostat. Ca hai cufa sd deu lam bing thach anh quang hpc. Ngoai ra cryostat nay con cd mot cua sd thach anh nfla nam đi xiing qua true cryostat vdi cufa sd cho anh sang rạ Cufa sd nay diing de do phd truyen quạ
Bd diSu bien anh sang gdm mdt ^ a nhua cd due 16, dupe gin tren true cua mot mdta; mot den 6V-12W dat đi dien vdi mdt photodiot sao cho den va photodiot d hai mat ciia dia quaỵ Khi dia quay, Iiic inh sang huynh quang chieu vao khe may don sic thi đng thdi anh sang ttr den 6V-12W ciing chieu vao photodiot; Iiic khe may don sic bi ^ a chin thi đng thdi photodiot ciing bi chin sang. Vi vay tfn hidu anh sang huynh quang chieu vao miy dan sac đng bd vdi tin hieu quang dien liy ra tir photodiot.
Tin hieu quang dien tuf photodiot dupe dua vao diSu khien bp phat tin hieu chuan. Anh sing huynh quang phat ra tii miu dupe hdi tu boi thiu kfnh TK2 vao may dan sac SPM2 do hang Carl-Zeiss-Jena ciia Cdng hda dan chu Diic sin xuat. May don sic diing lang kfnh thach anh cd đ tan sic tuyen tfnh 8nm/mm. Phd
huynh quang dupe phan tfch qua may don sic. Tfn hieu quang sau đ dupe đi thanh tfn hieu dien nhd dng nhan quang dien Model 77344 nhay trong mifen 160 nm
- 930 nm. Ong nhan quang dien dupe nudi bang the 1200 V tut ngudn chuyen dung
70705.
Tm hieu tuf dng nhan quang dien đng bp vdi tfn hieu chuan ca hai tfn hieu nay
dupe dua vao Lock-in Amplifier model 70707. Tit c i cac thidt bi nhu dng nhin
quang dien, ngudn nudi nhin quang dien, den thuy ngan va ngudn nudi den thuy ngan. Lock-in Amplifier deu do hang ORIEL USA sin suit.
• Model 3022 cua hang Yew Ha Lan sin xuat. Phd huynh quang dupe ghi lai dudi dang phan bd cUdng đ huynh quang theo budc sdng anh sang.
23.2 He do pho truyen qua
Bang cich bd tri lai thiet bi diing dl do phd huynh quang, ta cd thi xay dung
dupe he do phd truyen qua theo sa đ tren hinh 20.
Cich bd tri he do phd tniy^n qua chi khic vdi he do phd huynh quang d cic diem sau:
- Ngudn inh sang kich thfch la den anh sang tring, lOOW, day tdc thing, dupe nudi bang ngudn dn ip chuyen duog.
- Ngudn sing, miu (hoac lamen), cac thiu kfnh nam tren quang true, hudng tuf ngudn sang den khe may don sic. (adsbygoogle = window.adsbygoogle || []).push({});
Hinh 20. Sa do he do phd truyen qua
2 3 3 Cic phep do khac
Ngoai cac phep do ca ban la phd huynh quang va phd truyen qua, dupe thUc hien tai phdng thf nghiem d bd mdn Vat ly Dai cuang, mot sd phep do khac dupe thuc hien tai cac vien nghien ciiu khic nhu:
- Phd nhilu xa tia X cua cac mang ZnxCdị^S dupe do tai Vien Vat ly Ky thuat (VLKT) - Dai hpc Bach khoa Ha npi va Vien Khoa hpc Vat lieu (KHVL) - Trung tam Khoa hpc tu nhien va cdng nghe Qudc gia (KHTN vi CNCJG). (Tren may D 5000 ciia hangSiemens CHLB Diic)
- Phd Vi phan tfch tia X cua cac mang Zn^Cd^.^S dupe do tai phdng Kfnh hiln vi dien tut thudc Vifn ky thuit nhiet đi (KTND) - Trung tam KHTN va CNQG. (Tren may IMS 5300)
- B<& mat cic mang ZnxCdj.xS dupe chup anh hien vi dien tuf quet tai Vien VLKT - Dai hpc Bach khoa Ha ndi va Vien KTND - Trung tam KHTN va CNQG. Mdt sd miu dupe khao sat be mat tai phdng Hien vi dien tut - Vien Ve sinh dich tl va vien KHVL theo phuang phap replic (in lai).
- Phd phan giii thdi gian va thdi gian sdng huynh quang cua mang ZnxCd^.xS dupe do tai phdng thf nghiem Quang hpc vien KHVL bang ky thuat Boxcạ
- Mdt sd phd huynh quang tai 2K, kfch thfch bang laze Ar dupe do tai phdng thf nghiem khoa Vit Iy va Ky thuat do ludng Trudng dai hpc Linkoping - Thuy Dien.
- Mdt sd phd huynh quang kfch thfch bang laze N2 vdi budc sdng X = 337 nm
dupe do tai phdng thf nghiem Cooperman vien KHVL.
2.4. KetluSn
Bing viec bd sung, thay the cac thidt bi mdi va hien dai, cd đ chfnh xic cao,
an toan, chung tdi da xiy dung, cii tien va hoan thien cic he phun mang, he bdc bay
- He phun mang da dupe tu đng hda d mdt sd khiu nhu dn dinh nhiet đ bing bd khdng che, quay mau bing mdta nen cho phep tao miu d chd đ dn dinh. He cho phep thay đi tdc dp phun, nhiet đ de dl phii hop vdi yeu ciu phun tucng loai mang.
Tii hut da gdp p h ^ bao dam an toan cho ngudi Iam viec khi tidp xiic vdi hda chit đc haị
- He bdc bay chan khdng da dupc hoan thien, cd thi diing dl bdc bay cic kim loai lam dien cue len mang. Nhiet dp Id ngudn va nhiet đ d^ co the thay đi tiiy thudc vao kim loai bdc bay,
- He do phd huynh quang va phd truyen qua da boat dpng tdt, cd đ phan giai
dat yeu c^u v i cho phep do cac phd d cac nhiet đ tuf 77K đn nhiet dp phdng.
Ngoai ra chiing tdi con diing cac phep do khic ciia cac ca sd nghien ciiu ngoai tnrdng de cd them thdng tin cho viec doan nhin cac ket qua thuc nghiem.
Chuang 3. CHE TAG VA NGHlfiN CUU CAU TRUC CUA MANG Zn^Cd^.S