Magnetoelastic Effect in Perovskite Orthochromite HoCrO3.

It is well established that many material properties, such as multiferroicity, magnetoresistance, or magnetoelectricity, emerge from strong interactions of spins and lattice (phonons). An in-depth understanding of spin-phonon coupling is key to understanding these properties. We demonstrate strong spin-phonon coupling in HoCrO3 using powder X-ray diffraction measurements. Our investigations confirm magnetoelastic effects below antiferromagnetic phase transition, TN • 142 K. The lattice parameters and unit cell volume decrease normally with temperature up to ~ TN, but decrease anomalously below TN. By fitting the background thermal expansion for a non-magnetic lattice using the Debye-Grüneisen equation, we determined the lattice strain ΔVM due to the magnetoelastic effects as a function of temperature. We have also established that the lattice strain due to the magnetoelastic effect in HoCrO3 couples with the square of the ordered magnetic moment of the Cr3+ ion. [ABSTRACT FROM AUTHOR]