Magnetic symmetry of low-temperature phase of nickel-iodine-boracite Ni₃B₇O₁₃I

Abstract

We report the results of magnetic and magnetoelectric measurements on nickel iodine boracite Ni₃B₇O₁₃I. We concluded that the true symmetry of magnetically ordered phase is lower than m'm2’ from the existence of linear magnetoelectric susceptibility α₃₃. We noticed some features suggesting another phase transition about 25 K. The electric field during cooling across the transition temperature affected the bulk magnetic and magnetoelectric properties through the growth of preferred ferroelectric domains.