Neutron diffraction study of TbTi0.85Mo0.15Ge compound

Investigations made by susceptibility measurements and neutron diffraction experiments on the TbTi0.85Mo0.15Ge compound are reported. This compound cr ystallizes in the tetragonal structure of the CeScSi-type: (space group, 14 1mmm.). It exhibits two ferromagnetic transitions at T-C1= 280(3)K and T-C2 = 75(3) K. Below the first magnetic transition, the magnetization value an d coercive field are 3.6 mu (B) and 0.1 T, respectively, at 120 K. The magn etic structure consists of Tb ferromagnetic (001) layers (mu (rb) = 8.01(9) mu (B) at 120 K). Below the second magnetic transition, the maximum magnet ization is not reached and the coercive held is 1 T at 5 K. The magnetic st ructure consists of Tb ferromagnetic layers ferromagneticaly coupled along the c axis with the sequence (0, M-x, M-z)-(0, M-x, M-2)-(M-x, 0, M-z)-(M-x , 0. M-z) and at 1.5 K, M-x = 1.15(8) mu (B) M = 9.34(13) mu (B) M = 9.41(1 3) mu (B) (M-x is the projection of the magnetic moment on the XY plane, M- z the projection of the magnetic moment on the c axis). In this compound, n o local moment was detected on the (Ti0.85Mo0.15) site. (C) 2001 Elsevier S cience B.V. All rights reserved.