Optical spectroscopy study of Ca3(Ru0.91Mn0.09)2O7 single crystal in high magnetic fields

Sci Bull (Beijing). 2019 Jan 15;64(1):20-25. doi: 10.1016/j.scib.2018.11.013. Epub 2018 Nov 24.

Abstract

The magneto-optical spectrum, with magnetic fields up to 42 T, of double layered ruthenates Ca3(Ru0.91Mn0.09)2O7 (CRMO) single crystal is studied. Both the temperature and magnetic field induced insulator-to-metal transitions (IMTs) are observed via magneto-optical properties of the crystal. The critical magnetic field (H // c) of IMT for CRMO is found to be as large as 35 T at 5 K. The fine structure of optical spectra identified the antiferromagnetic/ferro-orbital-ordering configurations of Ru 4d orbitals at low temperatures. Meanwhile, the configuration of orbital polarization of such double-layer CRMO single crystal is discussed. These results suggest that the orbital degree of freedom plays an important role in the field induced IMT of multi-orbital system.

Keywords: High magnetic field; Insulator to metal transition; Optical spectroscopy; Ruthenates.