Ferromagnetic properties of the degenerate semiconductor Pb0.20Sn0.72Mn0.08Te.

摘要: We analyze the properties of a diluted ferromagnetic semiconductor ${\mathrm{Pb}}_{\mathit{x}}$${\mathrm{Sn}}_{1\mathrm{\ensuremath{-}}\mathit{x}\mathrm{\ensuremath{-}}\mathit{y}}$${\mathrm{Mn}}_{\mathit{y}}$Te for x=0.20 and y=0.08, two concentrations holes p=2.3\ifmmode\times\else\texttimes\fi{}${10}^{21}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}3}$ p=2.7\ifmmode\times\else\texttimes\fi{}${10}^{20}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}3}$. determine from field dependence magnetization magnon contribution to spontaneous magnetization; this is used calculate magnitude effective exchange integral ${\mathit{J}}_{1}$=4.8 K between nearest neighbors sample with higher p. The paramagnetic Curie temperature determined theoretically agrees within 30% that obtained measurements in regime specific heat estimated subtracted corresponding data. large value linear specific-heat coefficient \ensuremath{\gamma}\ensuremath{\approxeq}73 mJ/mol ${\mathrm{K}}^{2}$, as well spin reduction \ensuremath{\Delta}S\ensuremath{\approxeq}0.2\ifmmode\pm\else\textpm\fi{}0.05 atomic S=5/2 ${\mathrm{Mn}}^{2+}$ ion indicate an antiferromagnetic coupling Kondo type valence magnetic ions.