Magnetic field induced transitions in multiferroic TbMnO3 probed by resonant and non-resonant X-ray diffraction

TL;DR

This study investigates how magnetic fields influence the structural and magnetic order in multiferroic TbMnO3 using x-ray diffraction, revealing complex magneto-elastic interactions and phase transitions dependent on temperature and field orientation.

Contribution

It provides detailed experimental insights into magnetic field-induced transitions and the interplay between magnetic order and lattice structure in TbMnO3, including phase diagram development.

Findings

Strong interaction between rare earth and Mn magnetic orders.

Incommensurate to commensurate transition at critical fields.

Magneto-elastic interactions vary with temperature and magnetic field.

Abstract

Multiferroic TbMnO3 is investigated using x-ray diffraction in high magnetic fields. Measurements on first and second harmonic structural reflections due to modulations induced by the Mn and Tb magnetic order are presented as function of temperature and field oriented along the a and b-directions of the crystal. The relation to changes in ordering of the rare earth moments in applied field is discussed. Observations below T_N(Tb) without and with applied magnetic field point to a strong interaction of the rare earth order, the Mn moments and the lattice. Also, the incommensurate to commensurate transition of the wave vector at the critical fields is discussed with respect to the Tb and Mn magnetic order and a phase diagram on basis of these observations for magnetic fields H||a and H||b is presented. The observations point to a complicated and delicate magneto-elastic interaction as function of temperature and field.