Fig. 5: Thermal conductivity and AC susceptibility of Na2BaCo(PO4)2 for B // a.

a Magnetic-field dependence of thermal conductivity at different temperatures. For clarifying, the 151 mK, 252 mK and 380 mK curves are shifted upward by 0.5, 1.0 and 1.5, respectively. At very low temperatures, there are two minima on the κ(B) curves which disappear above 252 mK. b Temperature dependence of κ in different fields. No clear anomaly is observed. c AC magnetic susceptibility at different temperatures. There are two peaks in the low-temperature curves. d Magnetization curves obtained by integrating the AC susceptibility data and renormalized with the 3 T value. The dashed line indicates the Van Vleck paramagnetic background.