Structure and low temperature properties of SrB6

A detailed study of the room temperature structure of high duality single crystalline SrB6 has been made. Minute changes in interatomic distances may drastically affect the electronic spectrum of this compound. Electronic transport properties both at zero and non-zero frequencies above He-4 temperatures indicate that SrB6 is close to be a semiconductor. However, at very low temperatures this compound enters a metallic state with a low concentration of itinerant charge carriers. Possible correlation effects are indicated by anomalous temperature dependences of the electrical resistivity and the specific heat below 1 K.