Crystal structure and magnetic properties of Dy11Ni4In9

The work reports on the crystal structure and magnetic properties of Dy11Ni4In9. The compound crystallizes in the orthorhombic Nd11Pd4In9-type structure (space group Cmmm) with Dy atoms occupying five nonequivalent Wyckoff positions. Temperature dependences of specific heat as well as ac and dc magnetic susceptibility show a ferromagnetic-like ordering with T-C = 86 K and additional magnetic transitions at lower temperatures. The fit to the reciprocal susceptibility data above 180 K, in a paramagnetic state, follows the Curie-Weiss law and provides mu(eff) = 10.86 mu(B)/Dy-atom (close to the theoretical value of 10.65 mu(B) for the free Dy3+ ion) and a positive paramagnetic Curie temperature theta(p) = 28 K. Ni atoms are most likely nonmagnetic. The existence of a hysteresis loop below T-C indicates a change of magnetic properties. The coercivity field is large at low temperatures (50 kOe at 1.9 K) and decreases gradually with increasing temperature down to 0.01 kOe at 75 K. (C) 2013 Elsevier B.V. All rights reserved.