Adaptation of the modified pulse method for determination of thermal diffusivity of solids in the vicinity of the second-order phase transition points

The paper presents the adaptation of the modified pulse method for investigating temperature characteristics of thermal diffusivity in the vicinity of the second-order phase transition points. The principle of the adaptation consists in the modified in relation to the original method, development of the characteristics of temperature changes between boundary surfaces of a flat-parallel specimen after the laser shot onto its front surface. The application of this adaptation was illustrated with investigation into thermal diffusivity of nickel (99.9% wt) in the temperature range of 20–380°C. In all cases the measurement error was less than 3%, and the averaging interval for the measured values of thermal diffusivity was not greater than 1.2 K.