Chemical analysis of Fe concentration by absorption specirophotometry and op- .... Table 1. Results of the quantitative chemical analysis of Fe in single. Figure 1 ...
J A P AN E S EJ o u R N ALO FAp p LD l E PH Y S I C S VoL2 . 8N , o.,
1J A N U A R Y1 ,9 8 9 ,p p .1 2 1 5 f l ･
J I 1 ヽ ｣r -
p-r
Opt i calChar ace tr izat iT o IOfDepL e evel si nSi ngl eCr ysas tI し . . JR +1
OfCuGaS2Gr o
wnbyChem i calVaporTr ans por t Kas tuTANAK
A,
Koki
l s
Hl lSi , es ukeMATS UDA, E GAWAadK n as tuakiSATO* Yos hi t s uguHAS
L J. Lと ~ '~
p l ヽ トp ー 1 --
｣･ 二L∴ノ I ･r
1一-1 1 ∴p e｢ 一r I_
.■ こい Fa c ul l yo fTe cn h oo lg y,Tk oyoUnv ie r sl t y0 /Agr
L Cl u t ur ea n
d L T
L t ■ L Te cn h o/ o g y,Ko ga ne iT , oy koI4 8 L i l l ･ L 一二 1I ( Re c e i v e dS e p t e mb e r2 2 ,1 9 8 8 ; a c c e p t e df o rp u b l l C a t l O nNo v e me brl 9 , 1 9 8 8 ) ヽ= 一 一 ･ ■ . _ .
〔山 こ 】 .
1 ･ , , 1I
｢ , r
i 2. Expe r
i me na
tl
･一 一
J C L j on $1. I nr todt
･ L ドr ･-ト ⊥ LL I > -
. Ll
r 二P , r Jー_/L 1､ L二 '
l卜 一 J
. 】
･1 , 0
L
di nu no dp ea dn dF e -o rNi d o p es dil n gec r y s t a l so rCGS ua2g r o wnb yt h e Opc t ilb aas o r po t ins p e c t r aWe r eme a s u r e c h e mc il av a p o rr ta n s p o r He cn hl q u e . Ch e m aa ic ln a li y sso fFec o n c e n tt r ai o nb yas bo r p t i o ns p e c t r o po ht o me l r ya n do p t il c aca hr a c t e r l Z a t 1 0 ny b as bo r p L I O na n dpo ht o I u mn ie s c e n c e ( PL )s p e c t r o s c o p yn it h e s ema t e r i a l sr e v e a l e dtt h at h ema i n LCi r aemp u r i t i e sw
h i c
hd a r k e nu no dp ec dr y s t a l sa r eNl a n dF e . Th u eo tF e ee x ca l tt i o ns p e c t r u mOrt hi en f r a r e dPLd 3+ wa s a l s ome a s u r e dF .r o mt h it s .h1 e. 8e Vp e ao kl t h es t r o n gas bo r p t l Ob na n di n t r ou dc e db yr ta c ee FlP mu r i t i e swa si n t e r p r e t e di ne tr mso rt h er ta n s i t i o nf r o mt h ev a l e n c ea bn dt ot L hd ea n g l i n gb o n ds t a t eyr hbi d id z ewi t h3 do r b i L as lI KE YWORDS:s lJ n gec r y s t a l so fCGS ua 2 ･
i r o na n dn i cem kl lP u r i t i･ e sc o l o r a t 一 〇 noc fr y s t a l sas ･bo r p t i o ns p e c t r u m･ T .I 1 po ht o l u mn ie s c e n c es p e c t r u m,S p e c t r o po ht o me t r yo fi r o nL mP U r l t y ,d a n gn l lgb o n dh yr bi ds t a t e , l l g a n d f i e
l ds p e c t r u m
VI 2Smi e c onu dc t or saea r t t r a c t l ngmuhi c ne tr e s t トⅠ Ⅰ Ⅰ S
i ng
l ec r ys t a
l sofuno d pe d ad n F-o e rNi dope d ,s e df ort hepr e s e nte xpe r i me ns t,we r egr own asne wopo te l e c t r oni cma t e r i a l s ･The s ecmp o ouns t
h CuGaS2u d w
i byte hi o
di n
eCVTme t hod.Thes t arn t igmat e r i al s
we r e
i L h h e i c C ha Eu oy Sa r s i : e
h S i; u ;t u b r a e nh; dae a, di : ; C と. b 5 a e n V d: n ap t s ie a芸o en :g poy lc r ys t a l l i nepowde rofCu2 S,Ga Z S3 ,FS e ad n Ni S r e g
l O
nan
dp-
t ypec i on s eg d ee mi s s onduc t i vl t y.Theband6N) , it ne r e di nva c uo us i nge l e me nt sorCu( 5 N) ,Ga( i oft hi
sma t e r i a li spr omi s i ng f orne wl i ghte mi t t i ng S( f te
h 6 N) , Fe ( 4N) , an
d Ni ( 4
N) . Mi xu tr e s o
de vi c e s .Howe ve r ,t hec r ys t a
l l il nt yandt hepur i t yi nt he s e poy lc r ys t al l i nemat e r i a l s( ao b u
t5g)Wi t ht heappr opr i ae
t arr a t i owe r
es e a l e di nvac uoorao b ut3×1 0~5Tor r mat e r i al sar ef arbh ei ndc ompar e
dwi t ht hos ei nI I I Vor mol orap- t I トVIc ompounds .l nore drt ouet s hi sma t e r i a lf og e t he
rwi t
hi odi ne(2 1 mg/c c )adp n l ac e di nt of us e d pl i c a t i on,i ti se s s e nt i a lt oc onr toltes h pe c i e sofi m- s i l i c aampul e swi t hani nne rdi a me Thes e a
l -
t e ro
f】 3mm. fc t swhi c hma yr eu dc etee h f hi ce nc yof e Pur i t i e sa nddee dampue lswe r epa lc e di naf ur na c ewi t
has our c ee tmpe ト mi s s i on,andyt et he r ee xso it nl yaf e w au owt ht e mpe r au tr eof75 0o Cf or tr eof9 0 00 Ca ndagr t heba ndeg d ee r e por t son t he s ei nr ti ns i cad n e xr ti ns i cdee fc t s .The 1 0da ys .Obt a i ne dc r ys t al swe r eundope dCuGa2 S and aut hor shave be e ns t udi yng de e pl e v e l si nI I I l VI 2 t hos edope dwi t hFe( 010 , ･ 3an
dユ l om0%) 1 no
? ､ i na
l l yO･ anddope dwi t hNi(
no
ml na
l l y0. 1mo%)T l . hesa h pe sof o . n f dT , c a t n os r l S t l W . i pa ?. ar il G ≡ : ts :c C . ua i, r u r r ? t f l e e r S e て三t et h O ee :Pt : C at e P r ; a O E t he s ec r ys t al swe r epae ltl e t sc ,ou lmnsa ndne e dl e sandt he - t h n1c m Dopn igoft r ans
i t
i onme t ali snt ot hi sma t e r i ac laus e suni ypl Cli asz eofal lofte hc r ys t a l swasnotmor eta que opt or pt l On i nas i de.Bot hFe -dope dadu n ndope dc r ys t a l swe r ec o
l -
l C a
lphe no
me na
,s uc
h asi ne tns e abs bans dI ･ 2 )andli um ne s c e n
tc e ne tr s 3 )be l ow opt i c a lband or e ddar kge re nadb n e c amedare krwi t hani nc r e as ei n eg de s .
t heFec one tn. tThedomi nantc r ys t apa l lne swe r ede t e r I nt hi sr e s e a r c, h Wecr ar i e doutv ar i ousopt l Cl as t udi e s mi ne dasf11 2)byXr a yt e cnq hiue s . on t hi s ma t e r i alt o de t e r mie n how t oc onr tolt he Poa lr i z e dabs op It .l OnS pe c t r aOft he s ec ompoundswe r e as ur e dbe t we e n0. 5e Vad2 n . 5e V.Thet ypI Cli asz eor c r ys t a l l ii nt yandt heopt i c ap lr ope r t i e snr itoduc e dbyr tan- me .I n a
dd
i t
i on
,c onr tove r s y4, 5 )e hec r ys t al sus e d frt o he s eme as ur e me nt swa sabout s i t i on ao tms xi s t sast o t . her oughs i de swe r emi r r oトpOl i se hdus wht ehe rted h ar kge re nc oo lri nc r ys t a l sgr ownbyt he 8×3×1mm2T id oi nece hmi c av l aporr tans por t ( CVT)t e cn hi ques ic aus - i ngt hel ap
pn
igf i
l m S( 3I t m,】F L m ad03 n .l L m) .Poa lr i z e d e dbyna t i vedf ee c t soro fr e i gndee fc t sorFeF ore xampl e. as bor pt 1 0nS pe c t r aWe r eme as ur e da tr oom t e mp
e r au tr e I npar t i c ua lr ,Fei se as i l ys ubt si tt ue di nt ote h gr oupl l I onte( EPC) h 11 2)pl a n efr ol ih gt spoa lr i z e dp
a r ae l ll( s i t es ,i nc et hes ou lt i onl i mi torFei nI Ⅰ Ⅰ トⅤⅠ 2i sl O0%.I n andpe r pe ndi c ua lr( EiC)t oteC h a xs i.I ts houl dbe ore drt ode t e r in m et hi s ,
undope dadF n e -orNi dope d noe tdt ht at henoa tt i onEPCi sヮom i naa l ndonl y2/30f s l ngl ec r ys t a lsofCuGaS2
We r egr ow
nbyt hi se tcnq h iue, t hei yls SS ete( ne tns i t i ea l ongteCa h xI i nc h 11 2)pl ane andpoa lr i z e da bs or pt 1 0nS pe cr taaSWe l la sphoou tlmi ne s - doe snoti nc ld u ete h Ca xi s .He r e af t e rw , eus eEPC′t o
de s c r ie bt hi ss
i t ua
t i on.
c e nc eade n xc i tt ai ons pe c t r awe r eme as ur e. d Li ghtf r om a10 5 W hl aoge nt ungs t e nl ampwa sdi s dwi t haJ ASCOCT25 cmonocr homat or ,
C hop
pe
d pe r s e I Towo hmr e p r l nr te q u e s t sS h o u l db ea d d r e s s e d ･ byar oa tt i ng s e c t orad n poa lr i z e d bya Gr anpr l S m 【
1 2
1 3
Opl i c a lCh q r a c li e rz a f 1 0nO fDe e pI . e v e li snCuGqz S
( l ･∈ U)1N山U 一一 山｣ 山 OU
tce td by a poa lr i z e r .The t r ans mi t t e dl ih g t was dee phoo tmul t il pi e r( GaAst ype )a , s
i l i c onphoo tc e l landal i q. c ooe ldl nSbphoo tc e l l ui dni t r ogen/ /d The e xc
i tt a i o
nl ih g ts our c ef ort heme as ur e me ntort he --E phoou tli m ne s c enc e( PL) s pe cr tum wasanAr 'inl o as e r w i t
hs u
i t a
bl
eban
dpas shl t e r st os e l e c tanappr opr l ae t orteme h as ur e meto n ri nr far e d wave l e ngt h;54n 1 m f orbandeg d elmi u ne s c e nc e. l umi ne s c enc eand488nm f nan tie dat20K Thetmp e e r au tr eort hesmp a l e swasmai wi t haHer er fi ger ao tr .Thee t t e ih g twaschoppe d, mi dl te h ndi s per s e d byaJASCO CT25A monocr homat or / ∫ / U u l NP の F O O e O P O E .I E O 【 t ) O I L 2 I ＼ 9 ノ / ∫ ノ I ー it w hgr at i ngsbr az e dat1 . 6I t m( if nr ar e dr e go in)orat er e go in) .Thee xi tl ih g twasdee tce tdby 07 .5〝m ( vs ii b
l 1 ′ ) B f. tc e l l( if nr ar e dr e go in)Ora e i t heracooe
ld l nSb phoo PHOTON E 2 3 t phoo tc at hode ( phoo tmul vs ii bl e t il pi er wi h a GaAs r e go in) . y s t a l s bor p t l O nS Fi g ･1･P o lid a rz e as p e c t r aOi N rn ERG s l Y n g lc (V e er ) Fort heme as ur e me ntort hePLe xc i tt ai ons pe cr tum, u a2m oru no dp e d ( Hla n d#2)a n dFe d o p e d( 01 .1
9,03 . 6
7m0 1 %)CGS e a s u r e da t nt e r o o l t hel ih g tf r om ahao lge nt ungs t enlmpd a i s pe r s e dbya CT25 c monocr homat orwase mpl oye d.Thee mi t t e d l ih g tF r om tesmpew h a l asc danda gai ndi s per s e d hoppe byaNi kon P20mo 5
nocr homat or ,tew h ave l engt h of h PLs p ec t r um,andt hen c whi hwasf ixe
dt ot hepe akofte dt ee ce td by tec h ooe ld l nSb phoo tc e l l .Theobt an ie d pe ndanc
eor s pe cr tum wasc or r e ce tdF ort hes pe cr talde i l e.
t hee xc i tt ai onl ih g tme as ur e dbyat he r mop
Quant i tt ai veanay ls i sorFei ntec h r ys t as l wasc ar r i e d out by me ans of abs or pt i on s pe cr tophoo tme t r y as 6)Awe ih g edporo t inoft
hec r ys t as
lwasdi s s ol ve d fl ol ows. L 2 C L i ′ ///′ ∫ ∫ I i nc onc e nr tae td,hotni t r i cac i d.Af t e rtes h ou lt i onwas c ooe ldt or oom tmp e e r au tr e,l ar geamount sofc oppe r / C ' /′ 一 ~ l e c we r ermo e ve
d us i n
ge l e cr toy ls i swi t h aplt ai num e S O j t ne tt er aac e t i caci t r ode.The n,e t hl yene di ami d( EDTA) ノ ー ノ/ ー 一一 E ⊥ c g V ど ( ×O C j ′ 〈ノ // wasa
dde
dt omakt s hecoppe randnone fr r ousme t ali m1 2 l 3 ou lt i on.Spe cpur i t i e s ,s uc hasNi ( H) ,r e maii nngi nt hes PH t r ophoo tmet r i c dee tr mi nat i on was cr ar i e d outon a oLi a rz e OT b O s o r p t i o G g.2,Ma ∈ ) g n i 丘 e dp da N E N ns ER p e c Y( t reV) Shi mau z UVpe cr tophoo tme t e r . Fi e be am s 1 5 0-2 0 doubl h o w s )me a s ur e dar to o mt e mp e r a t u r e ･ Th dCu GS a2 en is es a to f u no dp e ( #1 10 Thec one tntofFewasdt ee r i m ne dat508nm,us l ng1, phenant hr ol i neasac oo lr l ngagent . E
上 c
B ,.0. 0 03
/ , , /
NO一 1d∝OS皿V
A
ヽ＼､､ヽ
J ′ , / /
6 7l l ! l
ヽ＼
peemrratu .
Uヒ山 OU
(T ･UJU)1N山 一 一
トd NO L
E
〝
一
$ 3. Exper
i mena tlRes ul t s Fi gur e1so h w s
ac onc enr tat i ondepende nc eoft heabdwi hFe.
t
Be l owt heabs or pt l OnS pe cr tai nCuGaS2dope
h os tc r ys t a, lt he r xs it sani ne tns e s or pt i one dgeofteh ee c h br oadabs or pt i onbandwi t w e aks ,AandB,whi htop gan lSi ne tns i t t nc r e as eort heFec ywi hani one tn. tFi gur e e s.As howsmagnはe pecr ta i a l 2s ds n undope d smp so h wni nt h
if s
igur e,abr oadabs or pt i onbands i i ml aro t t hati n teF h e dope
d smp a l e se xs it se ve ni n undope d s ampl eabs e e ni nFe e s .Thei ne tns or pt l Onb
ands dope d s ampl e nas s i dt otep r ans i e shasbe gne h hooo tinz iat i ont
t i on
7 mt ot hevae lnc ebandt heFe r e l ae tdl
e ve l sr eu dc )
f r o
･ The r eo fr eo , ure xpe r i me ntc l e ar l ys ug2' i ngFe" i nt oFe ge s tt s hatundope r ys t as lc ona ti i t i e s . dc nFei mpur Tabl e Is howste h r es ul tofquant i tt ai ve c he mi c al anay ls t s Of Fe i mpur
i t y dee tr mi ne d by te h s pe ct r ophoo tme t r y.Abs or pt l OnC r os sS e c t i onsprF e ea
t om dd euc e dF r om t h
eabs or pt l OnS pe cr taS
howni nFi g.1us l ngt hec one tntofFedt eer mi l l e dbyt hece h mi
c aa l nay ls i s ar es howni nFi g.3.Thec r os ss e c t i onort heu
ndoped s ampl e ssa ilr ge rt ha
nt hatort hei ne tnt yFe dope d i onal l s ampl e s ,id ni c a
t l ngt ht a undope dc r ys t al sc ona ti nsme o
F en i s i n g l e r' J･ F c aa n a li y sso a f p e a k a t O l 5 4 Tb a e.
c V r lt y e s l
i .
S芝
f e S c u
l t
Sa o s
f 2 t
三 三 d qu Ci a u ni i こi r v e e : s h Z e , -il S a mp l en a Fe00 .1 me F e0( . 氾3 F e0. uX) 1 Un d o p e dgl Uno dp e d#
Fec o n c e n ( r t i o nX a n omn ia l
a n a l y z e d
00 . ( 氾3 01
00 .1 02 0. 0 03 6 7
00 0 .1
0. 0 01 1 9
i e s 2 ot heri mpur i t 0. 1 0 XX 0 ) 3 1 4 1 or pt i i o
d
d p i e t cr i o t aofu I ntea h bs na ns nt Fe. s ampl e sw , eal s or oundape akat0 n. dope dandFedope d as s ocit ae d wi t htel h i gandf i e l dt r a 5 4e V,whi chmaybe ･ Ni 'i nCu
GaS2r e por t e dbyKauf mann s i t i on ( 2 T2 -2 E)of ge s t st ha
tundope dc r ys t al sal s o i sr e s ul ts ug8 )Th me as ur e
dapoa lr i z e dabs or pt i ons p c ona ti n Ni .Wet he n Cu
GaS2 .Asso h wni nFi g.4,abr oa e d cr tum i nNi 十一 dope d band s i mi l art ot hati nteF h e dope it ne n s eabs or pt l On d s a m
Ka t s uT∧ NA K AKk , o11 s HHSL ,eS ue k MA T S U D AY ,o s h i t s u g uHA s E G ^ WAa n dKa t s u a
k J S
A T
O
A 一一一一 Nr
e h ctrumruccmnntunsa peeeeelVTi H oooHlAm peeeppeo 2Kf00f6 oo . CGSiibbiddddd() aaauuu ysrssrrvnctcntct 2.ft o Hcurv psamesamssseaaeewnllidd oooy . Fiii xcttaons E6 g .. hb
lhhk sotoanrnnrAi pggstott eeeeewy ,,
fd soos et etcr e
f pyeerntt
H
... .
fii ntee
llfA aam ceee nsosnnnoosurr r . S )0 I a2 a eeeeppnccnsttruuumoofddCG H ( 2十iii514 j EK xctta PHOOTNENERGYeV m FiiPh ootl i ;: ト . () 5 nesc gu ..
o i
6 eepsort lOTh. iiFb nnga v
hA Pli L s parne ddhllf eeeynn -6 T)Ab l2 ysssmw ng ,iiiii iiiib totttto ascrcsaarrs 9) (4 .+iiibl) hhAd (514 etee 5 Th . ' fF toeooeee wassnunaaurvCGSdddi p 3 20 K rraarornanaon ,,iiiFl b 20 K y slVen td pames craeronmrtes ansomet pucont.iiiiiA fhd pneneeneexctatosctrumrttosmssomasurai g
fididdh ssonssenoe pactacaatttl u
hhhkGS dCiiiiml rrceeuaaaa Sb ppowsssooswt n 2 hhidd C pO ysssototootttmeerwaun uaaaCnnnGS 2 bidddiih ppaapssgntoroucurnntrrtoroc eeeee .P o f thbd tt g nnn .db pcorroesn a -iFGS bdbdddC tsorosprop eeeevnnn aau 10 2 .diiiddiThh lllfttttteeeeeeemssayyrrc onnoonng pullh PL ysssscrtt eeeeeegg crrrataaaaWo pumnnmbdd 10 ,diddd ifh i aaamsoosos oo pcenterereeeeeerrntrtw nnnneeeseeeeeassasar esetnt gmntenst attah gnnnnnth aaorrroorrmssseeeeeeee ouutddf nceeeneceaar peermn a rrreata eeeeettttOw teeureresusoOc easortoaeeth pth i poraooooootarrtrr gcThh eeeeeee iii ythitii n cnuSssssmaeaae ch nt ntttttii-ddbdddbbhl Fiiiii prrrpuuceeeemtsnatotnoaaso ttiii mmhN yyyti fdfddkillliD cuseeueesseonnonprlrpl rtrt rooth gpysssorth ucc umaaamonno petectceeecutt rnnN h ttti ss o aooi sacrrr mah pepeeeeosam guuv rnstThiii pmentmoresseeennort iii ppesuseeeeeesusscttttthhdNii mrf rrm a d a ete gumetatet mematrl art r ymaasoddib nn rersOSztonnnoott pcppcaraeeeeaar hihhiillbd n tstnnnsttsv cccr ononoonnnnn fliillbhddd ttttttpeeepeeecsumossssmmuorr aaaayiiiiiiiT nthfh curucrveeeeeexaoaosssom vv .iiiiidddbbh w() -dddf Fiiiiiib c -iiih ss x ,i t . $4 Dii ssscuon . ii hbqll aaaun atii ysssssuantit nati mg nveceeccppoor -h roiiiif pt 3% 0 0100 1 0 puyronmrtomorcncnttonea .Ud po nhbiikA d B nesn otooesrt pppcorresondt n aaaCGSFihhiif aaaaau 2:crrrrgngnnn b nll nnn iiiddl b n ngn gnn l lCGS fddfl nnn uu 2 , .llb r rrr ooo y , .bddbbb aaa aaaeenneeeenw .r diiiiiiiibhllh yysss -l ddddbk guuu -lff ad ld a .tlOnS .fWF oaaan Clihiiliih sssoo;nnnny lii lCGSF aeweeeaaaeewpgu 2: ,,l bb y eeeeexcooooounnnnttrastwassrwrraOvv yyuemsssmeesoccnnnpl SA ) 7 sorooor pgglThhhh ttdd tih pggsereesreerevaOOadi hh eee estssttth pth eroaaorroaooa gw poar lF ttii pppp cnnoooonnmeasueuesmmaessuseaer -ddmbb iti i Ahhh ppur aaag rssosnne essreeeiii etowccc .bdiiibbddH aaaaaaw一 -lldbC d tttttssssooeeeee .iiiddb ll bdbibdidiT nnn .li . ,iibdhihbdbdDA
. .,.,..
z
t hes ol i dc ur
5 〇 一
12
NE R G Y
(
e V) P H
1 O T
O
NE 2
′/
R U M I ∫
lO x5 ( l L E3)1N山 旧一 UI JL山OU N 1dtO l SEr V
5 0 dt j OS 皿V 2 lO x( TL UU)1N山 l UI J｣山OU No r_L
ti
J l I , :
′
′一一一一一→∫ I
ノ ′
ー ( ⊃ D) ^1l SN山1
I.
F i g . 4 .Po lidb a rz eas 5 o r p t i P o n HOTO
N ENERGY( e V) 3 n H l a n d# 2 )a dNi d o p e d( n o mn s il p e a c t l r y an 0 i .
I s m il n g ec r y s t a 一 sou fm no d p e d ( o l % ) CGS ua 2 e a s u r e d
at parOOmtmrreeteu .
1
( N U J UV NO 一トU山S SSOt ] U NO Ildt ] OS 瓜V
F i g .3 ,Ab s o T p t J O nr Co s sS e c t i o n si no n ee Fa G t Y( o mi e n Vu ) no dp e d d o p ec dr y s t a l so fCGS ua2 d e d u c e dF r o mt h es p e c t r as h o wni a n dF e b l e u s i n gt nF l g1 h ev a l u es h o wnn iTa
l O NS P E C T B S O R P T I
0
5
一 二二 1 ′I 2 PHOTON ENER 0
,
一
一 一′ . ′ 一 一 一 一 / 亡〟′一 ＼ . 一 ＼ コ/ -F eO . 0056 9 7 -, -
:
U N D O PEDt ll U N D○ PE Dt t 2 -. 一一 一F eO . 00日
E/ /C ' 一一---
u_ ,
Opl i ( P alChar d( ･ / e r l ' z o
I 1 0
1 7
0
/De e pLev e l sL nCuG S
｢ 一1
1 1･ J 】 ､ L l r J l 1- J
J J
, ■ 一 J L J
｢ II■ 1 Llr .･ ｢ J･ l r l も 三 ･ H . L r ' (J T･ ･ - 一 一一 一 T /
'･ . i I
J ｢
r
･ .･ - ･ ( - r L -r こ ･ l I
a (> a )^9∝uN u
byamol e c ua lr or bi t alc al c ua lt i oni na1 71 a t Om C l us t e r wi t hec e ne tr･"1I Thi ss ug hFei nt ge s tt s hatt heas bor pt i on bandi snots oe ll yc aus e dbyt hec har ge t r ans f e rt r ans i t i onr e ll atngt OteF h eat om. Ac di ng t o t he c al cuae ltd one c or e l e cr ton e ne r gy tt ona1 3 di mpur l e v e l s 川ofs ubt si ui i t i e sn i Si a ndGap,t he r e id n uc e ds tt ae s ,de noe tdt FR r t yar et hr e emai n3 di mpuri D b H( DBH: dr ,e r y s t al -
hl e
e s onanc e s ) CfRa nd t 2 ( CFR:c ligb dang n ondhyr er taer hdalc r ys t al f il eds ymbi d)l . nt i t i onsas me es shav er ee t r y,t he s tt ae e lt ai v ne r gy pos Rl sowe rt hant hee C F Rl e v ea l ndt he fl ol ows :t het ぎ F e ve lil Rl li sl rt Hl e c F e ve owe hant het Z D B e v e. lThet F F Rl e v e li s nt al wa yso lc ae tdi heval e nc eband,whe r e a st hee C F Rl e ve l me ot e r ge sn it heband一 gapr e gi onast heao tmi cnumbe rZ be c ome so lwe r ･Thee C F Ri swe l ll oc al i z e dadh n a smos t l y d-l i keca hr a c t e r ･Thet 2 D b Hl e v es lt ar t sne art het opofte h val e nc eband,ad n be c ome shi ge hri n teg h ap a sZ de c r e a s e s .Thet P B H` l SntO o nl ydl i kebta u l s ohsp a ca hr a c t e randawa v ef unc t i one xe tne ddi hec r y s t aa l nd nt whi c hbe c omel oc a l i z e dast hel e v e l sl oc at ede e pe r . i i na bs or pt i ons pe cr tumofCuGaS2 : Ni ,te he ne r gypos t i onwhe r etei h ne tns eabs or pt l Onbanda s s ume samaxsl ･ 8 6 e
V.
Thi se ne r gypos i t i oni i mumval u
ei sv e r yc l os e t ot hee ne r gypos i t i onor1 . 8 4e Voras bor pt i onbandBi n CuGa SZ : Fe.A ss umigt n ha tt he s epe aksaea r s s o
c i a t e d it w hDBH,t
os i t i onofbandBmayc or r hee ne r gyp
e s pondt ot het r ans
i t i o
nf r o
m tev h ae lnc eband( VB)t o t 2 D B
H,
r at he rt hant ha tf r om t P B
Ht ot h
ec onduc t i onband ( c
B) ,
s i nc et he VB･ t 2 D B "t r ans
i t
i on(na a l l owe dp-de xI c i tt ai on)Woul dhaveahih ge rne itns i t yt ha nt het PB H→cB t r ans i t i on( af or bi dde nd+se xca i tt i on) .TheDBH i san ant i bondi ngs tt aeo fr me df r omt 20r hehbi yrdi z a t i onoft t i ona t omsa ndoft bi t al soft r ans i h os t 20r bi t as l ofteh dangl i ngbondsofteg h r oupVIe l e me ntwhi c hoc c ur s whe nGai sr e mov e. d Thi ss tt aeac t sa stev h a c a nc yl i ke df ee ca t ndhasapos s i bi l i t yoro fr mi ngani ne tns eas bor pt i onband.Thi sas s umpt i oni sas los uppor t e dbyt hef ac t t ht a te h Fe 】十p e( ds t r ongl y hoou tlmi ne s c e nc PL)i se xc i t e l Onpe bya bs or pt ywe ybyabs or pt l On akA butonl akl fas bor pt i onpe kB.l ot , pe a akBi sr e l ae tdt heDBHl e ve l s c e nc l nce hd due t he u ne e wou
d be que o t t he lmi i ve r e c ombi nonr di a
t nat i on pr oc e s s t hr ough te h a t ih oc e
p ono
t onay l,t mul npr s s .Addi i l heas bor pt i onband Awoul da eCFRadtee ypos c bi t i onofa tas
t h
n h ne r g s or pt i onbandA wou
dal ober ans i t i onor l s e l ae tdtet h r VB- e
C F R .The s et r ans i t i onsar es ce hmat i c al l ys howni n . Fi g.7 † 一 ･･ L l l･{r ･l J Jl I JT-I l l r,J L L ･ - -ド-r r ･ ･ r･ ･ , 1 -ド . ^ f l ･ -Ll･ 11 ･ ｢ ･ ∴一, ｢ ･一 . .〔 L ｣. . ｢ -JL ､ま ･ rー L L= 止つ て r . L 'i L L Lp
∈⊥ C
F･ c h ee n e r g ya bn dl nCGS ua2: F i g . 7 .As c h c ma 【 i cv i e wo ft
J us j ons 9 5. Conc Opt i c a l abs or pt ∫ on S pe c t r a, quant i tt ai v ec he mi c al anal y s i sorFei mpur i t yadi n nr far e dPLme a s ur e me ns t hav ee l uc i dt ae dt hau t nne itnt i onal l ydope dFeandNii moo lr at i onort heunpur i t i e sar er e s pons i blf eort hegr e e nc dope dCuGa S2 .Wehav eal s os hownt ht a te h as bor pt i on bandi n1 VofCuGa
Ni s o. 8e c anbeas S2 :
FeandCuGaS2 : c i ae tdwi t hde e pl e ve l sc aus e dbyt hedangl i ngbonds tt ae hbi yrdi z e dby3 dor bi t al soft r ans i t i ona t oms . Q ]T
Ac kn" . eg . me ns .
Thea u
t hor
snoe t,wi t happr e c i at i on,t hatt hi swor k ys dbyaGr Ai df waspar
t i al l up
ce nt i Rc por t e ant i norSi honPr yAr 氾6 )f Re s e ar c 0 4( i or i t
e as( No.626 r om t he Mi yor
Educ eadC ns it r at t ur e. i on,Si ce nc n ul Ree fr enc e s )K.S aadT hIt n.Con. J i r a n i s h i :Proc.7t a t o ,H.Ts u n o d n .Te Te r r l a r yandMu/ ( i na r yCompouns d,Snowmo s sJ 986( Ma t e r i a l s Re s e a r c hS o c i e t y ,P i t t s b u r g, h1 9 8 7 )4 5 9 . )K. 2 S a t o , M. dH.
Ts u n oa d: J p n..
∫Ap p l . l s a wa , NTkh .aaa s h i a n PhS2 y,7( 1 9 8 8 )1 3 5 9 . )K. 3 S a t o,M. Mo r
i t a ..
SOk a mo t o ,, SMo r i t a , T. Ka mb a r a , K.1. Go na di r aa n dH. Tk ae n o s h i t a :Pr o g . Cr y s t .Gr o wt h良Ch a r a c t . 1 0( 1 9 8 4 )3 1 1 . )H.. dC. 4 e n ,A.
ot Sh cwa b: IYo n. Ba r dl ee b Gl z . e n e ,. BMe y e ra n Ph y s . S t a t u so Sl i d i( a )4 8( 1 9 7 8 )K1 4 5 . )A. 5 n a g a k i : Pr oc . Oo e ,. Sl i
d a .
M. Ya g i ,H.Ka wa g u c h i a n dT.l 7 J hl n. t Con /.Te ma r ya ndMu/ t i na r yCompouns d,Snowma s s
2 7 ･( i nら / i; : H n ' : 7: a
;
t r e i r i a
a L d Ri s ･ e a K r 三 : o s h O a 7 e i: 6 ,, も7 i i s P e i i ; s E u a r g g a h k ' u l 言 ; 7 ( ' 1 4 9 7 6 6( 1 9 7 4 ) Te r a n i s h i ,. KSt aoa n 7 )T. dK.
Ko no d: IP . h y s . S o c . J p n .
3 1 61 8 . u f ma y s .Re v . 811( 8 )U.Ka n n :Ph 1 9 7 5 )2 4 7 8 . St aoa n 9 )K.
dT. 1 9 7 4 )41 5 . Te r a n i s h i : JP .h y s . S o c . J p n. 3 7( Ka ma br a : JP .h y s . S o c . J p n . 3 1 9 7 4 )1 6 2 5 . 1 0 )T. る( Ac ae dmcr iPe s s , Ne wYo r k1 ,9 8 6 ) So/ i dSl ae lPh ys t c s( 1 1 )A. Zu n g e r : Vl o.3 9 , p2 7 5 .
J Er l LL :
. ,
′ ＼ _L ･ Il
