Abstract
BaCo2V2O8 consists of Co chains in which a Co2+ ion carries a fictitious spin 12 with Ising anisotropy. We performed elastic and inelastic neutron scattering experiments in BaCo2V2O8 in a magnetic field perpendicular to the c axis which is the chain direction. With applying magnetic field along the a axis at 3.5 K, the antiferromagnetic order with the easy axis along the c axis, observed in zero magnetic field, is completely suppressed at 8 T, while the magnetic field gradually induces an antiferromagnetic order with the spin component along the b axis. We also studied magnetic excitations as a function of transverse magnetic field. The lower boundary of the spinon excitations splits gradually with increasing magnetic field. The overall feature of the magnetic excitation spectra in the magnetic field is reproduced by the theoretical calculation based on the spin 12 XXZ antiferromagnetic chain model, which predicts that the dynamic magnetic structure factor of the spin component along the chain direction is enhanced and that along the field direction has clear incommensurate correlations.
Original language | English |
---|---|
Article number | 024439 |
Journal | Physical Review B |
Volume | 96 |
Issue number | 2 |
DOIs | |
State | Published - Jul 25 2017 |
Funding
The research at ORNL's HFIR was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, US Department of Energy. Work at NIST was supported in part by the National Science Foundation under Agreement No. DMR-0944772. This study was supported in part by the U.S.-Japan Cooperative Program on Neutron Scattering. The authors were supported by JSPS and MEXT KAKENHI Grants No. JP16K05494, No. JP15K05192, No. JP16H01082, No. JP24244059, No. JP25246006, and No. JP25220803. Computations were done on the supercomputers at the Japan Atomic Energy Agency and the Institute for Solid State Physics, the University of Tokyo.