BILs are related to GER, especially acid reflux. Location and duration of assessment for BILs needs to be standardized. Six-hour BILs could be substitutes for 24-h BILs. During analysis of MII-pH, more attention should be paid to BILs in the lower esophagus.

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IntroduclionThe large thermal stability ofexchange bias field (Hey) is a most determinant in a stable operation of a giant magoetoresistaiice(GMR) or tunneling magnetoresistance (TMR) spin valve Fenor. The thcrmal siability of an cxchmgc bias is Ii~gcly dcpcndcnl o n Ihc propcnics 01' an ;mIiCcrromgnct (AFM) [I]. For a SV with hFM consisting ofy-phase. the lower thermal stability compared to itn ordered AFM is the largc shortcoming for an application to a suh-niicron sensor. I n order tn improve a thermal slability. the synthetic ferrimagnetic layer was employed in a convenlional SV. or the optimal annealing process is known to improve on the magnetic properly at ramped tcmpcralurc.In this study. we have investigated the annealing conditions for a Mn-Ir-Pt based top and bottom convenrioiisl SVr and have evaluated the hlocking tempcl-;iturc ('I,) ;Ind the thema rtahility 01 H, , ai the ramped temperatun'. Thc change o l an interlace was confirmed lrom B RBS study.We prepared the 'bollom type' exchange bias layern(EBL) such as, Si(1W)md 30 A / NiFe. Cu 30 A jMn-lr-Pt 70 A I NiLFe Io0 A (Co-Fe I 5 A mi-Fe 35 A) p a 30 A. All fihns were deposited by dc magnetron sputtering. The 'top type' EHL was also prepared for comparing wilh a bottom EHL. The haqe pressure in the system was less than 2x IO-' l o r . The post annealing process wa'i done ill vacuum ofSx10 torr. The anncaling teniperature was varied from 120 C to 280 C . The applied field was froom I kOe to 5 kOe. Tlic Inmpnctic propcnics wcic mcasurcd hy a vihralinp SBIII[IIC magnameter. The Th was nreasured in antiparllel field uf 300 Oe. TheGMR were CVAlUk3tCd hy using 4 point probe methode. And the variation of surface roughness and microstructure was observed by atomic force microncopy(AFM) and HR-TEM. For an presence of interdiffusion layer. we u x d a Rutherford backscattering spcctroscupy(RBS).Results and discussion Figure 1 shows a variation of H,.. in a hottom EHL employing Ni-Fe seed layer. The H,, significantly increased at 250 "C. We thought that a ( I 11) lexture of Mo-lr-PI and Ni-Fe layer should he improved with increasing temperature. I n the case ofan EBL with Cu seed layer, although they dicl nut showed B lorgc increase, the H,, gradually increased. As shown in Fig. 2. the improved (I I I) peak or Mn-Ir-Pi and Ni-Fe ih cowisten1 with an incrcasc of Hex. But. the contribution of (I I I) texture c8iinot cxpl;iit> the decrease of H,, ill a top EBL, becluse thcy show :in increase of (I I I) texlure. It is though1 that lhe reorrangenienl olatoni a1 the interlitce should influence on llie different dependence between B top and hottom EBLs. And. we also invcstigsted the annealing iicld dcpendencc of EBLs. A hottom SV sho!ved a larger increitsc o f H, , ill il higher field. whercas tllc H. , o f a top EBL rapidly dccrcesed with a higher field. The nhore detailed results will be reported. 2mt*cdrgrR, 2 TiXlr,OFgRt, 21h0.1 IdC$lYCI (id (b) (c) Fig. 2. Variation of X-ray spectra of EHLs wilh an annealing temperature. (a) Bottom EBL 011 NiFc/T;t sccd laycr, (...