Low temperature thermal expansion measurements in PrV2Al20
We have measured thermal expansion of PrV2Al20 and LaV2Al20 from room temperature down to 2 K, using a capacitance dilatometer. Linear thermal expansion DL/L along [111] direction decreases monotonically on cooling in both materials. The extracted 4f electrons contribution of the linear thermal expansion coefficient a clearly shows a broad peak at 30 K which may correspond to the crystal electric field excited state at 40 K suggested in the previous specific heat study.