Magnetic and Thermodynamic Properties of Ce4RuAl

Abstract

Magnetic and Thermodynamic Properties of Ce4RuAl J.C. Debnath, A.M. Strydom, B.M. Sondezi, F. Tappe and R. Pottgen Highly Correlated Matter Research Group, Physics Department, University of Johannesburg, PO Box 524, Auckland Park 2006, South Africa Institut fur Anorganische und Analytische Chemie, Universitat Munster, Germany The results of magnetic susceptibility and heat capacity measurements are reported for the Ce4RuAl compound above room temperature to low temperature range (400 K to 0.34 K) and in the magnetic eld up to 7 T. The magnetic susceptibility χ(T ) exhibits a distinct anomaly at 0.95 K which most probably suggests a paramagnetic to antiferromagnetic phase transition. The magnetic susceptibility obeys the Curie Weiss law in the region 100 400 K and revealed an e ective magnetic moment μeff = 2.18 μB/Ce which is less than the value for free Ce 3+ (μeff = 2.54 μB). The paramagnetic Weiss temperature indicates net antiferromagnetic correlations. In the speci c heat a peak at 1.3 K supports the bulk nature of the phase transition observed in χ(T ). The Sommer eld coe cient is moderately enhanced in the paramagnetic phase, and suggests f c correlations among the electrons prior to magnetic ordering. The obtained Sommer eld coe cient γ behavior is consistent with the Anderson model-based theoretical predictions.