Abstract
We measured the normal-state Hall effect on the polycrystal of YBa2(Cu1-xMx)3Oy (M=Fe, Co) prepared by two kinds of heat treatments. The synthesized YBa2 (Cu1-xMx)3Oy (M=Fe, Co) was slowly cooled from 890°C in air. Some of them were annealed below 400°C in O2 gas (sample [O]s). The others were heated at 800°C in N2 gas followed by annealing below 400°C in O2 gas (sample [NO]s). It is considered that there is a difference in the configuration of substituent in the Cul-0 planes between [O]s and [NO]s: in [O]s the substituent is randomly located, while in [NO]s that makes clusters. The carrier density nH of [O]s and [NO]s in YBa2(Cu1-xCox)3Oy system decreases with an increase of x. In the case of YBa2(Cu1-xFex)3Oy system, nH Of [0]s decreases with an increase of x, while that of [NO]s is almost constant independent of x. The difference in the behavior of nH between YBa2(Cu1-xFex)30y and YBa2(Cu1-xCox)3Oy systems seems to be due to the difference of the microscopic structure around the substituent.
