Magnetic Phase Diagram of DyNi2Si2with Two-Dimensionally Modulated Spin Structures

Abstract

The fully mapped T - H (temperature-magnetic field) phase diagram of DyNi 2 Si 2 has been determined by heat capacity and magnetic susceptibility measurements. In zero magnetic fields, the heat capacity exhibits a small but distinct cusp at T 1 =3.7 K corresponding to the magnetic order-order phase transition, and a clear λ-type transition at T N =5.6 K. Except for the paramagnetic phase, three magnetic phases are found below T N and below the critical field H c =21.5 kOe. The results are discussed in comparison with recent experimental evidence which indicates the two-dimensionally modulated spin structures in the c -plane.