Enhanced Jahn–Teller distortion in the orthorhombic phase of La0.15Ca0.85MnO3 and Y0.15Ca0.85MnO3

Abstract

We report the results of neutron powder diffraction experiments on La0.15Ca0.85MnO3 and Y0.15Ca0.85MnO3. After an incomplete orthorhombic-monoclinic phase transition, the residual orthorhombic phase undergoes an enhancement of Jahn–Teller distortion of MnO6 octahedra. The degree of Jahn–Teller distortion is strongly influenced by coexisting monoclinic phase. Furthermore, ferromagnetism is closely associated with this Jahn–Teller distortion, rather than the buckling effect in the orthorhombic phase. Despite the low concentration of Jahn–Teller active Mn3+ ions, our result indicates an important role of Jahn–Teller effect on physical properties of the lightly electron-doped manganites.