Ferromagnetic Properties of ZrZn$_2$

TL;DR

This study investigates the ferromagnetic properties of ZrZn2, revealing its weak itinerant ferromagnetism, critical behavior near T_C, and non-Fermi liquid resistivity, supported by comprehensive experimental measurements.

Contribution

The paper provides detailed experimental characterization of ZrZn2's magnetic, transport, and thermodynamic properties, offering insights into its weak itinerant ferromagnetism and critical phenomena.

Findings

Critical exponents beta=0.52 and delta=3.20 determined near T_C

Resistivity exhibits non-Fermi liquid behavior with n≈1.67

Specific heat shows mean-field-like anomaly at T_C

Abstract

The low Curie temperature (T_C approx 28K) and small ordered moment (M_0 approx 0.17 mu_B f.u.^-1) of ZrZn2 make it one of the few examples of a weak itinerant ferromagnet. We report results of susceptibility, magnetization, resistivity and specific heat measurements made on high-quality single crystals of ZrZn2. From magnetization scaling in the vicinity of T_C (0.001<|T-T_C|/T_C<0.08), we obtain the critical exponents beta=0.52+/-0.05 and delta=3.20+/-0.08, and T_C=27.50+/-0.05K. Low-temperature magnetization measurements show that the easy axis is [111]. Resistivity measurements reveal an anomaly at T_C and a non-Fermi liquid temperature dependence rho(T)=rho_0+AT^n, where n=1.67+/-0.02, for 1<T<14K. The specific heat measurements show a mean-field-like anomaly at T_C. We compare our results to various theoretical models.