EFFECT OF HYDROGEN DOPING ON THE MAGNETIC-PROPERTIES OF GD2CUO4

We report the results of ac-susceptibility and dc-magnetization measur ements for HyGd2CuO4 (0 less than or equal to y less than or equal to 0.54). It is shown that H doping lowers the weak ferromagnetic compone nt in the material. The distinct hysteresis loops observed at T = 77 K for both non- and hydrogenated samples change its shape with y. The m agnetic ordering temperatures T-N(Cu) and T-N(Gd), as determined from the temperature dependencies of ac-susceptibility, remain unchanged wi th samples' hydrogenation. This result seems to indicate that extra el ectrons are not doped onto the Cu-O planes of Gd2CuO4. The frequency d ependencies of chi'(omega, T) and chi''(omega, T) for both y = 0 and y = 0.15 samples are analysed. The maximums of chi' and; chi'' found at about 200 K are considered in terms of susceptibility dependence on t he spin-lattice relaxation time (tau). The anomalies in ac-susceptibil ity found recently in Gd2CuO4 at T-a = 8 K and T-b = 9.5 K decrease si gnificantly with y. Results are discussed in the context of available data on 214T'-type compounds.