Spin-Peierls Magnet CuGeO3
The study of the magnetic and resonance properties of the single crystal CuGeO3were initiated by Petrakovskii and co-authors who first discovered the sharp decrease of the magnetic susceptibility for three main axes of the crystal at the temperature below 14 K. Later Hase and co-authors also observed the similar effect and interpreted it as a spin-Peierls transition. The effect was interpreted in terms of the S=1/2 uniform antiferromagnetic chain which is settled down in the 3D crystal below some critical temperature, and a second order phase transition to a dimerizated singlet state with the energy gap spectrum of magnetic excitations is likely to arise. The main investigations proving that the CuGeO3crystal is the spin-Peierls magnet are discussed in this review with the special emphasis on the following facts: the singletization of the ground magnetic state, the presence of the structural phase transition corresponding to the lattice doubling along the axis of the chain, the energy gap character of the magnetic excitation spectrum, the anomaly of specific heat at the transition temperature, and the specification of the magnetic phase diagram. The magnetoelastic properties of the CuGeO3crystal arealso discussed here.
KeywordsElectron Spin Resonance Magnetic Susceptibility Inelastic Neutron Scattering Magnetic Excitation Resonance Property
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