Record Details

BaV3O8: A possible Majumdar-Ghosh system with S=1/2

DSpace at IIT Bombay

View Archive Info
 
 
Field Value
 
Title BaV3O8: A possible Majumdar-Ghosh system with S=1/2
 
Creator CHAKRABARTY, T
MAHAJAN, AV
GIPPIUS, AA
TKACHEV, AV
BUTTGEN, N
KRAETSCHMER, W
 
Subject HEISENBERG-ANTIFERROMAGNET
MAGNETIC-SUSCEPTIBILITY
SUPERCONDUCTIVITY
FRUSTRATION
TRANSITION
VANADATES
CHAIN
STATE
 
Description BaV3O8 contains magnetic V4+(S = 1/2) ions and also nonmagnetic V5+(S = 0) ions. The V4+ ions are arranged in a coupled Majumdar-Ghosh chainlike network. A Curie-Weiss fit of our magnetic susceptibility.(T) data in the temperature region of 80-300 K yields a Curie constant C = 0.39 cm(3)K/mole V4+ and an antiferromagnetic Weiss temperature theta = -26 K. The chi(T) curve shows a broad maximum at T similar or equal to 25 K indicative of short-range order (SRO) and an anomaly corresponding to long-range order (LRO) at T-N similar to 6K. The value of the "frustration parameter" (f = vertical bar theta/T-N vertical bar similar to 5) suggests that the system is moderately frustrated. Above the LRO temperature, the experimental magnetic susceptibility data match well with the coupled Majumdar-Ghosh (or J(nn) -J(nnn) Heisenberg) chain model with the ratio of the nnn (next-nearest neighbor) to nn (nearest neighbor) magnetic coupling alpha = 2 and J(nnn)/k(B) = 40 K. In a mean-field approach when considering the interchain interactions, we obtain the total interchain coupling to be about 16 K. The LRO anomaly at T-N is also observed in the specific heat CP(T) data and is not sensitive to an applied magnetic field up to 90 kOe. A 51V NMR signal corresponding to the nonmagnetic vanadium was observed. Anomalies at 6 K were observed in the variation with temperature of the 51V NMR linewidth and the spin-lattice relaxation rate 1/T-1 indicating that they are sensitive to the LRO onset and fluctuations at themagnetic V sites. The existence of two components (one short and another long) is observed in the spin-spin relaxation rate 1/T-2 data in the vicinity of TN. The shorter component seems to be intimately connected with the magnetically ordered state. We suggest that both magnetically ordered and nonlong-range-ordered (non-LRO) regions coexist in this compound below the long-range-ordering temperature.
 
Publisher AMER PHYSICAL SOC
 
Date 2014-10-17T04:17:53Z
2014-10-17T04:17:53Z
2013
 
Type Article
 
Identifier PHYSICAL REVIEW B, 88(1)
http://dx.doi.org/10.1103/PhysRevB.88.014433
http://dspace.library.iitb.ac.in/jspui/handle/100/15928
 
Language en