ISSN:
1434-6036
Keywords:
65.50 + m
;
75.10.Jm
;
75.50.Ee
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract We present an investigation of the spin-Peierls transition atT SP=14.5 K in polycrystalline CuGeO3 through specific-heat and thermal-expansion measurements. Clear second-order phase-transition anomalies are found in both properties atT SP, although only a small entropy of S≈0.1 Rℓn2 is released at the transition. Most of the entropy is released atT SP〈T〈150 K, where the temperature dependence of the magnetic contribution to the specific heat as well as the thermal expansion exhibit extrema atT *≈40 K. These are caused by one-dimensional antiferromagnetic fluctuations along the Cu chains, possibly accompanied by structural fluctuations. Using Ehrenfest's relation, a hydrostatic pressure coefficient (∂T SP/∂p)p→0 ≈ (0.45±0.06) K/kbar is derived.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01324522
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