³¹P-NMR Study of Low-Energy Spin Excitations in Spin Ladder(VO)₂P₂O₇and Spin DimerVO(HPO₄)0.5H₂OSystems

Modeling of the magnetic susceptibilities of the ambient- and high-pressure phases of(VO)2P2Johnston1, Saito2, Azuma3 et al. 2001Phys. Rev. B384573View full textAdd to dashboardCite

“…10 When χ(T ) calculations for the spin ladder model were eventually done, 14 it was found that the same experimental χ(T ) data set 10 could be fitted by the spin ladder model to the same high precision as for the very different alternating-exchange chain model. 14 The existence of a spin gap was subsequently confirmed and its value estimated from NMR measurements of the 31 P Knight shift 31 K(T ) and nuclear spin-lattice relaxation rate 31 (1/T 1 )(T ), 15,16 from χ(T ) (Ref. 17) and inelastic neutron scattering 18 measurements on polycrystalline samples at low temperatures, and most recently from elastic constant measurements 19 on a single crystal in pulsed magnetic fields up to 50 T at T = 1.6 K and from Raman scattering intensity measurements on single crystals at low temperatures, 20 as listed in Table I.…”

Equation of state and spin-correlation functions of ultrasmall classical Heisenberg magnets

“…3,4 A common feature of these organic-based molecular magnets is that intermolecular magnetic interactions are extremely weak compared to those within individual molecules, i.e., a bulk sample can be described in terms of independent individual molecular magnets. As examples of molecular magnets with ultrasmall numbers of embedded paramagnetic ions we mention: Two dimer systems, one 5 of V 4ϩ ͑spin Sϭ1/2) and the second consisting of 6 Fe 3ϩ ions ͑spin Sϭ5/2); a nearly equilateral triangular array 7 of V 4ϩ ; a nearly square array 8 of Nd 3ϩ ͑total spin j ϭ9/2); a regular tetrahedron array 9 of Cr 3ϩ ͑spin Sϭ3/2); and a nonregular tetrahedron array 10 of Fe 3ϩ ions. Also noteworthy is the pyrochlore antiferromagnet Tb 2 Ti 2 O 7 , although distinct from the class of organic molecules yet sharing the feature that the Tb 3ϩ ions ͑total spin jϭ6) reside on a network of very weakly coupled tetrahedra.…”

Low-temperature nuclear magnetic resonance investigation of systems frustrated by competing exchange interactions

“…In order to check whether this difference is due to the effect of spin diffusion, we measured 1/T 1 at different applied fields at T = 15 K. [132]. In Fig.…”