Magnetic ordering induced magnetostriction dynamics via pulsed magnetic field in the polar magnet CaBaCo₄O₇

The magnetization, magnetostriction, and electric polarization of CaBaCo4O7 single-crystal samples were investigated under static and pulsed magnetic fields. Experimental results show that the ferrimagnetic order and metamagnetic transition occur in a lower-temperature region. At 4.2 K, with the increase of the applied magnetic field, there is a transition from multidomain to single domain at about 2 T, and then with the further increase of the magnetic field, the spin of cobalt ions (Co1 and Co4 ions) changes from noncollinear to collinear. Along with this magnetization process, magnetostriction also exhibits two continuous processes: magnetostriction related to magnetic domain rotation and magnetostriction related to the increase of spin collinearity. Especially in pulsed magnetic fields, the magnetization, magnetostriction, and polarization transitions induced by magnetic order occur almost in the same critical magnetic field. We assume that in the system, the magnetic order can further polarize the orbital via spin-orbit interaction, resulting in strong magnetostriction.