title: Magnetostructural phase transition assisted by temperature in Ag-αMnO2: a density functional theory study.
abstract: A crystalline material formed by parallel chains of silver atoms inside one-dimensional tunnels of hollandite manganese dioxide, Ag-αMnO2, is investigated through first-principles total energy calculations. Two different magnetic phases have been identified; one structure containing linear Ag chains with an antiferromagnetic ordering in the direction perpendicular to the MnO2 tunnels for T = 0 K (I4/m) and another configuration with zigzag Ag chains in a non-magnetic regime for higher temperatures (P21/c). According to phonon dispersions, both structures are stable. On the other hand, the structure with linear Ag chains in the non-magnetic state is unstable. A critical temperature of Tc≃ 125 K for the magnetostructural phase transition between the two stable structures I4/m and P21/c is predicted.
authors.affiliation: Benemérita Universidad Autónoma de Puebla, Instituto de Física, Apartado Postal J48, 72570 Puebla, Mexico. fsanchez@ifuap.buap.mx.
authors.forename: Francisco Sánchez
authors.initials: FS
authors.lastname: Ochoa
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Huang
authors.forename: Xingfu
authors.initials: X
authors.lastname: Tang
authors.forename: Gregorio Hernández
authors.initials: GH
authors.lastname: Cocoletzi
authors.forename: Michael
authors.initials: M
authors.lastname: Springborg