Magneto-Elastic Coupling in a Sinusoidal Modulated Magnet Cr$_2$GaN
Hui-Can Mao1,2, Yu-Feng Li3, Qing-Yong Ren4,5, Mi-Hai Chu6, Helen E. Maynard-Casely7, Franz Demmel8, Devashibhai Adroja8, Hai-Hu Wen3, Yin-Guo Xiao6*, and Hui-Qian Luo1,9*
1Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China 2University of Chinese Academy of Sciences, Beijing 100049, China 3National Laboratory of Solid State Microstructures and Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China 4Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China 5Spallation Neutron Source Science Center, Dongguan 523803, China 6School of Advanced Materials, Shenzhen Graduate School, Peking University, Shenzhen 518055, China 7Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation, Lucas Heights NSW-2232, Australia 8ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot Oxon OX11 0QX, United Kingdom 9Songshan Lake Materials Laboratory, Dongguan 523808, China
Abstract：We use neutron powder diffraction to investigate the magnetic and crystalline structure of Cr$_2$GaN. A magnetic phase transition is identified at $T \approx 170$ K, whereas no trace of structural transition is observed down to 6 K. Combining Rietveld refinement with irreducible representations, the spin configuration of Cr ions in Cr$_2$GaN is depicted as an incommensurate sinusoidal modulated structure characterized by a propagating vector $k=(0.365, 0.365, 0)$. Upon warming up to the paramagnetic state, the magnetic order parameter closely resembles to the temperature dependence of $c$-axis lattice parameter, suggesting strong magneto-elastic coupling in this compound. Therefore, Cr$_2$GaN provides a potential platform for exploration of magnetically tuned properties such as magnetoelectric, magnetostrictive and magnetocaloric effects, as well as their applications.
2022, Vol. 39 
