Thermodynamic properties of (Ca,Sr)2RuO4(Ca,Sr)2RuO4 in magnetic fields

We have studied the influence of a magnetic field on the thermodynamic properties of Ca2-xSrxRuO4Ca2-xSrxRuO4 in the intermediate metallic region with tilt and rotational distortions (0.2⩽x⩽0.5)(0.2⩽x⩽0.5). We find strong and anisotropic thermal expansion anomalies at low temperatures, which are suppressed and even reversed by a magnetic field. The metamagnetic transition of Ca1.8Sr0.2RuO4Ca1.8Sr0.2RuO4 is accompanied by a large magnetostriction. Furthermore, we observe a strong magnetic-field dependence of cp/Tcp/T and that can be explained by magnetic fluctuations.