The e.ffect of simultaneous doping . of Pll in TJ..Q,6 htyer of 'T'lJ-xPb. Ba2Ca2Co_309- o s perconductors

Abstract

Tn   t·  p.a,p r        We hae  reported it;vestigations O:U   the·  effeot of

simtHtaneous s·ubs'tituti9n   of  :Pb . a;t tbe,1'1-based .IJPercqndl,lctor was·

prepar.d by adcling; an .amoun· 0f Pb t. the TIJ-PbxBa;iCa2CuaOo'ti cor:npound. The: usu;d solid'7state  teactin  meJ;}Jo.d                                                             haS be:eu. applied t:mdr optimum  co_nditjon..· auJk po.lycrys.talline sari;lples.  hf!ve -been

p.reparQ by  the  tWo step .soli_d   tate  re.ctip:n  proeess;  It  has  bee 1

• ohsewedthat the gj'own Il1-xPh.x.BaiGa2Cu30:6(with x = <.tbo,· O.'l 0 •

0_:49 'Q.$Q. atld . Q.40) CO(Ie$pQnds to the t 2J phase. Thl X"' ay da:ta Â·of:

the Sa.mple showe4  tetragonal >Stmciture  ith high  ratio .afTI.-1223

SQpeFCO!lductiti,g ph e. r·e Â§aptpls .show.ed  a transitjort tertljn.etatutes

Ti?<\\'IIJSCI)W ic.h were  ti6 .K.. 12'3 K,_ 1"29.  J<_, 131 ' L34 K  at  {x = 0.,0,.

O.JO,   .0.20.  .0, 30'     <tn   Â·  .4-0.) tespectivdy,   and  the  ttansiti:on:

temperatures at zero resistance  Tc(otn   were          lOl , HIS,. H)112 a,n-d

ns K_,   r.es_p.cl,'.tiv ly;.   R.esistivitie's.   were         m asure4   at   cliffetr¢.nt

.  tempeta:tures unde11 zero magn tic .fields and 'the data w t hl erp:tetea.

Alrthe S41TIPleS pr.eparation wi;;o2 f19w' we fCtun-d Jhat the 0:;! fl9W  in

our:sanipi.e.S prgdQcd high-: Pha;se s.uperco"nducto.r .

X-Tay di:ftract1oh aQaly$is, showed an ·incr.ease .of :the c-'axis. lat!iioe

eorutlli)t fQr tile :san1p.hS' doped with ph as c.ompared  with. fu s<Z have

:no t;Jb contentIt was found Â· that be chan.g. of  the pb concentrations

of all our s:amp'le.s . Produeed ·     a ¢hangNil  the density    Pilh ·Cfa a;nd

volume 'fractiPJi V t'il(1 22-3>.