Measurement of the thermal diffusivity in bamnf4by means of its intrinsic pyroelectric response

A measurement of the thermal diffusivity (D t) as a function of temperature in BaMnF4 using a technique which employs the material's own pyroelectric effect is reported. D t varies from 25 × 10−3 cm2/sec to 5 × 10−3 cm2/sec over the temperature range 20K to 280K. No anomaly in D t is observed in the region of the structural phase transition at ∼250K. However, in this same region, an abrupt change in d 2 P/dT2 (the slope of the pyroelectric current) is observed.