Mцssbauer effect study of $\mathrm{Bi_{0.8}La_{0.2}FeO_3}$ multiferroic on $^{57}$Fe nuclei

The parameters of hyperfine interactions in the $\mathrm{Bi_{0.8}La_{0.2}FeO_3}$ multiferroic have been measured by Mцssbauer spectroscopy in the temperature range of $87$–$850$ K. It has been found that the spatial spin-modulated structure that exists in $\mathrm{BiFeO}_3$ is destroyed in the substitution of $\mathrm{La}$ for $0.2$ mol $\%$ of Bi and the homogeneous antiferromagnetic structure appears. The temperatures of the magnetic (Nйel temperature, $T_{\mathrm{N}}=677\pm3$ K) and ferroelectric (Curie temperature, $T_C=773\pm3$ K) transitions and the Debye temperature $(\Theta=431\pm12)$ have been measured.