Using magnetostriction to measure the spin-spin correlation function and magnetoelastic coupling in the quantum magnet NiCl_2-4SC(NH_2)_2

We report a method for determining the spatial dependence of the magnetic exchange coupling, dJ/dr, from magnetostriction measurements of a quantum magnet. The organic Ni S = 1 system NiCl_2-4SC(NH_2)_2 exhibits lattice distortions in response to field-induced canted antiferromagnetism between H_{c1} = 2.1 T and H_{c2} = 12.6 T. We... Show more