Lattice effect on thermal diffusivity in double perovskite molybdenum oxide investigated by mirage technique

Lattice effect on the thermal diffusivity has been investigated in double perovskite A 2 FeMoO 6 (A= Ca, Sr and Ba) by means of mirage technique at 300 K. We find that the thermal diffusivity increases form 35 mm 2 /s for A= Ca to 41 mm 2 /s for A= Ba. Considering the change of the Fe-O-Mo bond angle from 152.4° for A= Ca to 180° for A= Ba, the larger thermal diffusivity for Ba compound has been ascribed to the enhanced hybridization between transition-metal d and oxygen p states due to the larger Fe-O-Mo bond angle and hence the wider one-electron bandwidth (W).