2018/06/11 by Zarzycki, A., Rams, M., Goerlich, E. A. +1
#FOS: Physical sciences #Strongly Correlated Electrons (cond-mat.str-el)
paper · doi:10.48550/arxiv.1806.03923
Thermodynamic and transport properties of Sr1-xCaxRuO3 with a calcium concentration x ≥ 0.8 were investigated at low temperatures and in external magnetic field. The investgations revealed a Landau Fermi liquid (LFL) behaviour characterized by specific heat C/T = const and resistivity ρ∼ T2 and an anomalous non-Fermi liquid (NFL) behaviour with ρ∼ T5/3 and a quasi-logarithmic increase of C/T with decreasing temperature. The T--x and T--B phase diagrams which separate both regions were prepared for the investigated materials. Then, the experimental behaviour of C/T and ρ(T) were compared with predictions of the self-consistent renormalization (SCR) theory of spin fluctuations. Within this approach, C/T(T) was well described up to 20 K. The SCR parameters y0, y1 and T0 inferred from specific heat analysis allowed to describe properly ρ(T) up to approximately 5 K. In addition, the resistivity data were analysed within the `hidden Fermi liquid' theory of Anderson, obtaining very good descritption of the experimental behaviour up to about 25 K. An anomalous increase of the C/T ratio already in the LFL region below 2 K in very weak magnetic fields (0.2--0.3 T) was identified as caused by the Schottky anomaly induced by ferromagnetic clusters embodied into the essentially paramagnetic materials.