Coexistence of double alternating antiferromagnetic chains in (VO)_2P_2O_7 : NMR study

Abstract

Nuclear magnetic resonance (NMR) of 31P and 51V nuclei has been measured in a spin-1/2 alternating-chain compound (VO)_2P_2O_7. By analyzing the temperature variation of the 31P NMR spectra, we have found that (VO)_2P_2O_7 has two independent spin components with different spin-gap energies. The spin gaps are determined from the temperature dependence of the shifts at 31P and 51V sites to be 35 K and 68 K, which are in excellent agreement with those observed in the recent inelastic neutron scattering experiments [A.W. Garrett et al., Phys. Rev. Lett. 79, 745 (1997)]. This suggests that (VO)_2P_2O_7 is composed of two magnetic subsystems showing distinct magnetic excitations, which are associated with the two crystallographically-inequivalent V chains running along the b axis. The difference of the spin-gap energies between the chains is attributed to the small differences in the V-V distances, which may result in the different exchange alternation in each magnetic chain. The exchange interactions in each alternating chain are estimated and are discussed based on the empirical relation between the exchange interaction and the interatomic distance.

10 pages, 11 embedded eps figures, REVTeX, Submitted to Phys. Rev. B

Cited by in corpus (17)

• Magnetic light scattering in low-dimensional quantum spin systems
• Strong frustration due to competing ferromagnetic and antiferromagnetic interactions: magnetic properties of M(VO)2(PO4)2 (M = Ca and Sr)
• Analytical Bethe Ansatz for closed and open gl(n)-spin chains in any representation
• Modeling of the Magnetic Susceptibilities of the Ambient- and High-Pressure Phases of (VO)_{2}P_{2}O_{7}
• Magnetic properties of Ag(2)VOP(2)O(7): an unexpected spin dimer system
• Magnetoelastic coupling and spin excitations in the spin-gap system (VO)${}_2$P${}_2$O${}_7$: A Raman scattering study
• Magnetic properties of (VO)_2P_2O_7: two-plane structure and spin-phonon interactions
• Alternating-spin-chain compound AgVOAsO${}_4$ probed by ${}^{75}$As NMR
• Two energy scales of spin dimers in clinoclase Cu3(AsO4)(OH)3
• Spin Diffusion in the S=1/2 Quasi One-Dimensional Antiferromagnet α-VO(PO_3)_2 via 31P NMR
• Analytical Bethe Ansatz for open spin chains with soliton non preserving boundary conditions
• Singlet ground state in the spin-$1/2$ weakly coupled dimer compound NH${}_4$[(V${}_2$O${}_3$)${}_2$(4,4${}^{\prime }$-$bpy$)${}_2$(H${}_2$PO${}_4$)(PO${}_4$)${}_2$]$\cdot$0.5H${}_2$O
• Strong-coupling magnetophononics: Self-blocking, phonon-bitriplons, and spin-band engineering
• NMR, magnetization, and heat capacity studies of the uniform spin-1/2 chain compound Bi6V3O16
• Two types of alternating spin-$\frac{1}{2}$ chains and their field-induced transitions in $\epsilon$-LiVOPO${}_4$
• Charge ordering and ferrimagnetism in the strongly correlated $\beta$-V${}_2$PO${}_5$ single crystal
• NMR characterization of spin-1/2 alternating antiferromagnetic chains in the high-pressure phase of (VO)2P2O7