UPt3 exhibits anomalous, possibly time-fluctuating antiferromagnetic (AFM) order below 6 K. Th substitution induces conventional AFM order with the same magnetic structure. Recent μSR studies on U 1-xThxPt3 for 0≤x≤0.05 showed that the transition into the conventional AFM state was sharp for x=0.05, but broadened for x≤0.02 (Phys. Rev. B 84 (2003) 224421), indicative of a crossover behavior. We present X-ray diffraction and transmission electron microscopy (TEM) results that show no significant material inhomogeneity in those samples. However, specific heat measurements corroborate the μSR measurements and show signs of an increase near 7 K for x>0.01. This supports the conjecture that Th impurities slow down the fluctuating AFM, rendering them observable on the timescale of thermodynamic measurements.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering