Nearly itinerant ferromagnetism in CaNi2 and CaNi3

TL;DR

This study reports the synthesis and characterization of CaNi2 and CaNi3, revealing their proximity to ferromagnetic instability and strong ferromagnetic fluctuations, with implications for understanding itinerant ferromagnetism.

Contribution

The paper provides new single-crystal growth methods and detailed magnetic analysis of CaNi2 and CaNi3, highlighting their near-ferromagnetic behavior and fluctuation effects.

Findings

High Stoner factors indicating proximity to ferromagnetism

Pronounced field dependence of magnetic susceptibility at low temperatures

Observation of T^3lnT contribution to specific heat

Abstract

Single crystals of CaNi2 and CaNi3 were successfully grown out of excess Ca. Both compounds manifest a metallic ground state with enhanced, temperature dependent magnetic susceptibility. The relatively high Stoner factors of Z = 0.79 and Z = 0.87 found for CaNi2 and CaNi3, respectively, reveal their close vicinity to ferromagnetic instabilities. The pronounced field dependence of the magnetic susceptibility of CaNi3 at low temperatures (T < 25 K) suggests strong ferromagnetic fluctuations. A corresponding contribution to the specific heat with a temperature dependence of T^3lnT was also observed.