Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8155066 | Journal of Magnetism and Magnetic Materials | 2016 | 29 Pages |
Abstract
Magnetization and high-field ESR measurements have been performed to study the magnetism of nanocrystals of α-CoV2O6, an Ising spin-chain system without triangular lattice but presenting interesting 1/3 magnetization step. The results demonstrated the antiferromagnetic (AFM) enhancement and gradual suppression of the 1/3 magnetization step in nanoparticle samples. Within the framework of core-shell model consisting of the AFM core spins and the uncompensated/disordered shell spins, the AFM enhancement below TN=13 K is a result of enhanced shell disorder with weak ferromagnetism. This AFM enhancement, along with the suppression of saturation magnetization, results in the suppression of 1/3 magnetization step. Furthermore, the paramagnetism of the shell was confirmed by our high-field ESR measurements. The time-dependent magnetization suggests the presence of spin-glass-like freezing. This is expected for nanoparticles with surface shell disorder with ferromagnetic correlations, but is not expected for bulk material of α-CoV2O6 without spin frustration. These findings demonstrate that size tuning is an effective parameter for controlling the ground state of α-CoV2O6.
Keywords
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
H. Shu, Z.W. Ouyang, Y.C. Sun, M.Y. Ruan, J.J. Li, X.Y. Yue, Z.X. Wang, Z.C. Xia, G.H. Rao,