Title :
The specific heat of NdNi5
Author :
Radwanski, R.J. ; Kim-Ngan, N.H. ; Kayzel, F.E. ; Franse, J.J.M.
Author_Institution :
Van der Waals Lab., Amsterdam Univ., Netherlands
fDate :
3/1/1994 12:00:00 AM
Abstract :
The specific heat of NdNi5 measured on a single-crystalline specimen from 1.5 K to 250 K has been analyzed in terms of two electronic subsystems, i.e. conduction-electron and f-electron subsystems. The conduction-electron subsystem is found in LaNi5 to be characterized by a value of the Sommerfeld coefficient γ of 36 mJ/K2mol f.u. The contribution of the f-electron subsystem to the specific heat shows a λ-type of peak at Tc of 7.4 K and a non-pronounced Schottky-type of peak above Tc. The f contribution is well described within a single-ion Hamiltonian that includes the crystalline-electric-field (CEF) and exchange interactions of the Nd3+ ions. The exchange parameter and the full set of the CEF parameters associated with the hexagonal symmetry have been evaluated. The ground state Γ8 for the Nd3+ ion in NdNi5 is highly anisotropic with the magnetic moment lying within the hexagonal plane. This ground-state results from higher-order charge multipolar interactions
Keywords :
crystal field interactions; exchange interactions (electron); ferrimagnetic properties of substances; neodymium alloys; nickel alloys; specific heat of solids; 1.5 to 250 K; NdNi5; Sommerfeld coefficient; conduction-electron subsystem; crystalline-electric-field interactions; exchange interactions; f-electron subsystem; hexagonal symmetry; multipolar interactions; single-crystal; single-ion Hamiltonian; specific heat; Atmospheric measurements; Atomic measurements; Crystallization; Intermetallic; Lattices; Magnetic anisotropy; Neodymium; Perpendicular magnetic anisotropy; Phonons; Temperature;
Journal_Title :
Magnetics, IEEE Transactions on
