Determination of the local magnetization caused by short-range order from the paraprocess magnetostriction dependences of a ferromagnet

It is shown that the local magnetization caused by short-range order can be deduced from the paraprocess magnetostriction dependencies of a ferromagnet. The local magnetization vs. temperature is plotted for ferromagnets CdCr₂Se₄ and Cd_0.8Zn_0.2Cr₂Se₄. The value of spontaneous volume striction at T=0 K is obtained from the experimental results and shown to be in good agreement with estimates obtained from thermodynamic considerations. The local magnetization at the Curie temperature for these ferromagnets is shown to be about (0.2-0.3)×M₂(T=0 K). The temperature range ΔT of the short-range order region is greater for Cd_0.8Zn_0.2Cr₂Se₄ than for CdCr₂Se₄