Thermal expansion measurements of the quasi-one-dimensional conductor K0.30MoO3

The charge density wave (CDW) dynamics of the quasi-one-dimensional conductor K0.30MoO3 shows two different regimes depending on the temperature: a strongly damped CDW motion above ∼50 K∼50 K and CDW motion with almost no damping below ∼50 K∼50 K. In a search for a characterization of this CDW behaviour, we performed thermal expansion measurements on K0.30MoO3 single crystals in the temperature range 4–250 K. In addition to the anomaly observed at the Peierls transition at 180 K along the [102] direction, an anomaly is observed at ∼50 K∼50 K along the [−201][−201] and [102] directions. The results are discussed in relation with the change in the CDW rigidity at ∼50 K∼50 K.