SUSCEPTIBILITY OF Y2CU2O5HX

Temperature dependence of the real and imaginary part of the ac suscep tibility was measured for Polycrystalline Y2Cu2O5Hx for x = 0, 0.34, 0 .72, 1.52, and 1.88. It was found that the effective magnetic moment o f the copper ions decreases with increasing hydrogen content. Also, th e height of the maximum at 13 K associated with the antiferromagnetic transition of Cu ions decreases while its position shifts slightly tow ard higher temperatures. Another maximum at about 5.8 K disappears alm ost completely for hydrogen content of x = 1.52. A steady magnetic fie ld also reduces the height of the lower temperature maximum, shifting it negligibly. For an external magnetic field above 200 Oe, this maxim um disappears completely.