Exchange Strictions of Ferromagnetic Compound Mn₅Ge₃

抄録

Thermal expansion of a ferromagnetic compound Mn₅Ge₃ was determined from X-ray powder diffraction data at temperatures ranging from 100 to 400°K. From the thermal expansion curves, values of exchange striction along a and c axes were deduced. They are positive along the a axis and negative along the c axis respectively, and this fact leads to a weak dependence on pressure of the Curie temperature. Using the present data of the exchange striction, the pressure coefficient of the Curie temperature, (1/T_c) (dT_c⁄dp), was estimated to be 14×10⁻¹³ dyn⁻¹ cm², which agreed well with the directly measured values of 18×10⁻¹³ dyn⁻¹ cm² by the present writers and 15×10⁻¹³ dyn⁻¹ cm² by Block and Pauthnet.