Abstract
We have conducted a comprehensive investigation into the magnetic properties of the chiral multiferroic material CoTeMoO6. In contrast with the previous claim of canted antiferromagnetic order with ferromagnetic components [Y. Doi et al., J. Solid State Chem. 182, 3232 (2009)], our investigation reveals an antiferromagnetic ground state with compensated moments, providing an interesting platform for exploring exotic material properties. Through careful measurements of magnetization under a series of applied fields, we demonstrate that there exist two sequential field-induced magnetic transitions in CoTeMoO6, with one occurring at 𝐻𝑐1=460 Oe along the 𝑎 axis, and the other at 𝐻𝑐2=1.16 T with the field along the 𝑏 axis. The values of 𝐻𝑐1 and 𝐻𝑐2 exhibit strong angular dependence and diverge with different rates as the applied field is rotated 90 ° within the 𝑎𝑏 plane. This reflects the distinct nature of these transitions, which is further supported by the different critical behavior of 𝐻𝑐1 and 𝐻𝑐2, characterized by the values of 𝛾, in the function of 𝐻𝑐=𝐻0(1−𝑇/𝑇𝑐)𝛾. Furthermore, we have demonstrated that there exist structural and magnetic twin domains in CoTeMoO6 that strongly affect the experimental measurement of their macroscopic properties. Intriguingly, these twin domains can be related to the orthorhombicity/chirality of the crystal structure with the space group 𝑃21212. We further explored the magnetic and structural domains with uniaxial pressure and polarized light microscopy. Our results suggest that CoTeMoO6 could be used as a unique platform for investigating the intriguing physics involving intertwined degrees of freedom. The tunability of the underlying domain distribution and its strong anisotropy could also be useful for developing functional devices and applications.
