ChiTOTig 2: CAC PHlTOfNG PHAP THV'C NGHlfM
2.1.3. Phiin x^ magnetron
Cic hf phun xa DC vi RF trin day cd mpt han chi co bin li hifu suit sd dyng difn tu khdng cao do difn tu chi di theo dudng thing tir cathode din anode vi do d6 chi cd khi ning ion hda cic phan tu khi tren quing dudng đ. Trong cic ciu hinh phin xa niy, chi vai phin trim nguyin tu khi tro dugc ion hdạ Ting khi nang ion hda chat khi cua cic difn tu thu d p , ngudi ta phii v ^ hinh hf thdng d ap suat tuang doi caọ Di nang cao hifu suit su dyng difn tu trong khi vIn duy tri dugc ap suit d mdc thq), ngudi ta dimg tu trudng di lii qu)^ dao ciia cac diin tu theo nhdng quy dao cong. Thiit bi thyc hifn giai phip ky thuat nay li phiin xa magnetron (Magnetron Sputerring). Clu hinh ciia hf phiin xa manhitrdn dugc cii tiin blng each dit mpt nam cham d dudi bia vat lieu (hinh 2.5). Tir trudng ciia nam cham cd tic dyng bay cic difn tu vi ion d gin be mat bia lam tang sd lin va ch^m gi&a cic diin tu va cic nguyin tu khi vi lim ting
hieu suat ion hda cua chung.
He phiin xa manhitrdn cd cic uu diim nhu tdc dp ling dpng cao, sy ban phi cua cac dien tu va ion trin mang giim, han che su ling nhiet dp de va sy phdng difn phat sang CO thi dugc duy tri d ap suit phun xa thap hem. Ngoai ra, do hifu suit ion hda ciia cac dien tir thu cap tang nin mat dp plasma
tang va trd khang cua khdi plasma giam. Kit ~ "^"^
si ting dugc đng phdng difn, hoic li si giim dugc difn ip nudi hf thdng so vdi hf phun xa khdng dugc ting cudng blng tu trudng.
Cd thi su dyng phun xa magnetron cho ca mpt chiiu va xoay chiiụ K^ thu^t
phun xa magnetron cho phep chi tao cic loai ming kim loai, difn mdi, bin din trin nhiiu loai di khac nhau, cic mang cd thi chi tao vdi cic tinh chat, chuc ning dinh trudc vdi mpt quy trinh dinh trudc vdi tdc dp tao ming vi chat lugng ming rlt caọ 2.2. Nghiin cuu cau true bing phutnig phip nhilu xa tia X
Tia X tdi bj phin xa trin cic mit phing m^ng song song vi cich nhau mOt khoang d, sdng phin xa trin mdi mat phIng mang cd cudng dp rat yeu, nhung nlu chiing giao thoa vdi nhau thi cd thi nhan dugc chiim tia nhiiu xa cd cudng dO rlt manh.
Gpi 9 la gdc tdi, diiu kif n di nhan dugc chiim tia nhiiu xa cd cudng dO cgc d^i gpi li diiu kif n Bragg:
2dsine = n>. (2.1) Ta thu dugc nhung kit luan sau:
- Vi sinO < 1 nin chiim tia nhiiu xa manh chi xiy ra đi vdi cic hue x^ c6 budc
sdng X < 2d. Trong tinh thi d cd A, do đ d ciing cd A, nghia la hifn tugng nhilu x^
chi cd thi xay ra vdi tia X.
- Trong mpt tinh thi thudng cd nhiiu hf mit phIng mang (hkl), moi hf mjt niy niu thda man diiu kien Bragg diu cd the cho cac eye dai nhiiu xạ Tuy nhiin diy mdi li diiu kifn can, cd rihimg mat phang mang thda man diiu kifn Bragg nhung vin khdng cho cue dai nhiiu xa,
Blng each phan tich phd nhiiu xa tia X, cd thi xic dinh cic hf mit phIng m^ng va khoang each dhki giua hai mit phIng gan nhau nhat trong mdi hf. Khoang cich niy phy thudc vao hing sd mang vi chi sd Miller (hkl) ciia mat phang mang. Bing 4 cho thIy khoang each dhki đi vdi mpt sd hf tinh thi dan gian. Nhu vay, niu biit gii trj ciia dhki va chi sd Miller (hkl) ciia hf mit phIng mang ta cd the tinh dugc hang sd mang cua tinh thẹ
Bang 4: Khodng each d^u giira cdc mat phdng mgng trong cac A# tinh the Hf tinh thi Lap phuang Tu giic Tryc giao Lyc giac
Khoing cich dhu
a y/h'-^k'-^l' â \^ á b' c' -1/2 -1/2 "(4/3Xh' + hk + k' l ' ' â ""c^ -1/2
De nghien cim cau tnic ciia mang mdng ngudi ta chiiu tia X tdi ming mdng vii
gdc tdi nhd (< 5\ nhd chiiu xiin, tia X di dugc mpt d o ^ dudng dii trong ming, cyc
dai nhieu xa tang lin din muc cd thi quan sit dugc. Vi dy niu chiiu tia X nghiing gic 6 so vdi bi mat, chiiu dai tia tdi trong ming ting 10 so vdi khi chiiu thing, vdi gic tdi nhd han 1^ dudng di ting hon 100 lln. Di tia X ludn ludn di dugc d o ^ dudng dii trong mang mdng phai giu nguyin gdc tdi nhd, cd nghia li chiim tia vi mlu phii dteg yen, chi xoay detector di ghi cudng dp nhieu xạ Diiu đ si din tdi khdng dim bio dieu kien tu tieu, ngudi ta khic phuc blng cich lim nhihig detector die bift nhu hinh
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