TY - JOUR
T1 - Magnetic structure and spin dynamics of the quasi-one-dimensional spin-chain antiferromagnet BaCo2V2O8
AU - Kawasaki, Yu
AU - Gavilano, Jorge L.
AU - Keller, Lukas
AU - Schefer, Juerg
AU - Christensen, Niels Bech
AU - Amato, Alex
AU - Ohno, Takashi
AU - Kishimoto, Yutaka
AU - He, Zhangzhen
AU - Ueda, Yutaka
AU - Itoh, Mitsuru
PY - 2011
Y1 - 2011
N2 - We report a neutron diffraction and muon spin relaxation mu SR study of static and dynamical magnetic properties of BaCo2V2O8, a quasi-one-dimensional spin-chain system. A proposed model for the antiferromagnetic structure includes: a propagation vector (k) over right arrow (AF) = (0,0,1), independent of external magnetic fields for fields below a critical value H-c(T). The ordered moments of 2.18 mu(B) per Co ion are aligned along the crystallographic c axis. Within the screw chains, along the c axis, the moments are arranged antiferromagnetically. In the basal planes the spins are arranged ferromagnetically (forming zigzag paths) along one of the axes and antiferromagnetically along the other. The temperature dependence of the sublattice magnetization is consistent with the expectations of the three-dimensional (3D) Ising model. A similar behavior is observed for the internal static fields at different muon stopping sites. Muon time spectra measured at weak longitudinal fields and temperatures much higher than T-N can be well described using a single muon site with an exponential muon spin relaxation that gradually changes into an stretched exponential on approaching T-N. The temperature-induced changes of the relaxation suggest that the Co fluctuations dramatically slow down and the system becomes less homogeneous as it approaches the antiferromagnetic state.
AB - We report a neutron diffraction and muon spin relaxation mu SR study of static and dynamical magnetic properties of BaCo2V2O8, a quasi-one-dimensional spin-chain system. A proposed model for the antiferromagnetic structure includes: a propagation vector (k) over right arrow (AF) = (0,0,1), independent of external magnetic fields for fields below a critical value H-c(T). The ordered moments of 2.18 mu(B) per Co ion are aligned along the crystallographic c axis. Within the screw chains, along the c axis, the moments are arranged antiferromagnetically. In the basal planes the spins are arranged ferromagnetically (forming zigzag paths) along one of the axes and antiferromagnetically along the other. The temperature dependence of the sublattice magnetization is consistent with the expectations of the three-dimensional (3D) Ising model. A similar behavior is observed for the internal static fields at different muon stopping sites. Muon time spectra measured at weak longitudinal fields and temperatures much higher than T-N can be well described using a single muon site with an exponential muon spin relaxation that gradually changes into an stretched exponential on approaching T-N. The temperature-induced changes of the relaxation suggest that the Co fluctuations dramatically slow down and the system becomes less homogeneous as it approaches the antiferromagnetic state.
KW - Superconducting materials
KW - Superledende materialer
U2 - 10.1103/PhysRevB.83.064421
DO - 10.1103/PhysRevB.83.064421
M3 - Journal article
VL - 83
SP - 064421
JO - Physical Review B (Condensed Matter and Materials Physics)
JF - Physical Review B (Condensed Matter and Materials Physics)
SN - 1098-0121
IS - 6
ER -