Magnetic and optical properties of transparent RbNiF₃

Magnetic and optical data on single-crystal RbNiF3 are presented. We conclude that this material is ferrimagnetic, rather than antiferromagnetic as previously reported, with a transition temperature of 139°K and a saturation moment of 21 emug at 4.2°K. The basal plane is the preferred plane and the out-of-plane anisotropy is 106 ergscc. The Faraday rotation measured along the c axis at 77°K and 80 of magnetic saturation exhibits a peak value of 400°per cm at a wavelength of 4950 and values of 250°to 50°per cm in the region 5000 to 6000 where the optical absorption is lowest. © 1967 The American Institute of Physics.