Magnetic-field-induced instability of the cooperative paramagnetic state in Zn xCo 4-x(OD) 6Cl 2

Abstract

Using elastic and inelastic neutron scattering techniques with and without application of an external magnetic field H, the magnetic ground states of Zn xCo 4-x(OD) 6Cl 2 (x=0,1) were studied. Our results show that for x=0, the ground state is a magnetic long-range ordered (LRO) state where each tetrahedron forms an "umbrella"-type structure. On the other hand, for x=1, no static ordering was observed down to 1.5 K, which resembles the behavior found in the isostructural quantum system Zn xCu 4-x(OD) 6Cl 2. When H field is applied, however, the x=1 system develops the same LRO state as x=0. This indicates that the x=1 disordered state is in the vicinity of the x=0 ordered state. © 2012 American Physical Society.