Nuclear spin relaxation in ordered bimetallic chain compounds

Abstract

A theoretical interpretation is given to recent proton spin relaxation-time (T_1) measurements on NiCu(C_7H_6N_2O_6)(H_2O)_3$\cdot$2H_2O, which is an ideal one-dimensional ferrimagnetic Heisenberg model system of alternating spins 1 and 1/2. The relaxation rate T_1^{-1} is formulated in temrs of the spin-wave theory and is evaluated by the use of a quantum Monte Carlo method. Calculations of the temperature and applied-field (H) dependences of T_1^{-1} are in total agreement with the experimental findings. T_1 behaves as $T_1^{-1}\propto H^{-1/2}$, which turns out an indirect observation of the quadratic dispersion relations dominating the low-energy physics of quantum ferrimagnets.

5 pages, 4 figures embedded, to appear in Phys. Lett. A

References in corpus (10)

• Elementary Excitations of Heisenberg Ferrimagnetic Spin Chains
• Replica-exchange molecular dynamics simulation for supercooled liquids
• Thermodynamic Properties of Heisenberg Ferrimagnetic Spin Chains: Ferromagnetic-Antiferromagnetic Crossover
• Thermodynamics of the (1,1/2) Ferrimagnet in Finite Magnetic Fields
• Magnetic Properties of a Quantum Ferrimagnet: NiCu(pba)(D_2O)_3 . 2D_2O
• Schwinger boson mean field theory of the Heisenberg Ferrimagnetic Spin Chain
• Magnetic Properties of Quantum Ferrimagnetic Spin Chains
• Critical Behavior of Anisotropic Heisenberg Mixed-Spin Chains in a Field
• Magnetic and Critical Properties of Alternating Spin Heisenberg Chain in a Magnetic Field
• Low-Energy Structure of Heisenberg Ferrimagnetic Spin Chains

Cited by in corpus (2)

• Intrinsic double-peak structure of the specific heat in low-dimensional quantum ferrimagnets
• Modified spin-wave description of the nuclear spin relaxation in ferrimagnetic Heisenberg chains