Field-induced magnetic order in the singlet-ground-state magnet CsFeCl3 -: art. no. 224426

The field-induced magnetic order in the singlet-ground-state system CsFeCl3 (H parallel to c) has been studied by the measurements of the magnetization M-parallel to (the ferromagnetic component along the c axis) and the magnetic neutron scattering from M-perpendicular to (the antiferromagnetic component in the c plane). The field dependence of M-perpendicular to has clearly shown that the field-induced ordered phase is described by the order parameter < S-x > (M-perpendicular to=g(perpendicular to)mu(B)< S-x >). The development of the spin correlation and the incommensurate-commensurate phase transition have been observed in the field region of 5 T < H < 6 T, and the comparison has been made with the phase boundary at H similar to 10 T (H > H-c). Two possible magnetic configurations have been suggested for the commensurate three dimensional long-ranged order phase. The frustration and the magnetostriction effects have been discussed.