Chromium Tribromide
chromium tribromide is a two-dimensional ferromagnetic material that may be used in ultrathin spintronics. It is one of the few ionic ferromagnetic crystals with a hexagonal layer structure and a Curie point of about 36degK.
Magnetic ordering in CrBr3 is observed at a band edge near 20 000 cm-1. This band edge is accompanied by exceedingly large magnetic rotations of the axis of polarization. The intensity of the amplitude modulation is proportional to the component of magnetization along the line of sight in the crystal. The trigonal field effect is pronounced, and the magnetic order is attributed to a ferromagnetic exchange coupling between the single-ion trigonal field and the odd-parity vibronic field.
Various chromium trihalides show interesting magnetic properties and are therefore promising candidates for future magnetoelectronic devices. In addition, the unique 2D structure of CrBr3 and its unusual magnetic ordering open new possibilities for the fabrication of magnetoelectronic devices based on two-dimensional systems and in heterostructures with different materials. The crystal field spectra are investigated with special attention to the broad, spin-allowed 4T2 and 4T1 bands, as well as the temperature dependence of the dipole strengths.