Giant volume magnetostriction and its connection with colossal magnetoresistance and lattice-softening La 1−xM xMnO 3 (M=Ca, Ag, Ba, Sr)

Abstract

Giant volume magnetostriction, reached ∼6×10 −4 in magnetic field 8.2 kOe, is found in La 1− x M x MnO 3 (M=Ba, Sr, Ca, Ag) manganites near Curie-point T C. Volume magnetostriction ω and magnetoresistance exhibit similar dependence on temperature and magnetic field in T C region that is explained by the presence in these compounds of magnetic two-phase ferromagnetic–antiferromagnetic state due to strong s−d and/or d−d exchange. Maximum | ω|-value depends from radius of M-cation: it is larger the larger the difference | R A− R La3+| and A-cation size variance σ 2, where A=La 1− x M x .