ISSN:
1434-6036
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract Static and dynamic behavior of an-component classical model atd=4 has been investigated assuming a coupling to a fluctuating lattice displacement field. Solutions of renormalization-group (RG) equations are given for elastically isotropic and anisotropic systems, and the temperature dependences of elastic constants and of the corresponding damping coefficients are calculated. For isotropic and weakly anisotropic systems it is found that forn〈4 the critical regime can be split into a rigid regimet〉t s , and a compressible regimet〈t s , wheret=(T−T c )/T c andt s is a crossover temperature. In the rigid regime, the logarithmic correction factors characterizing deviations from Landau theory have the same form as in systems without elastic coupling; in the compressible regime the exponents are renormalized by the coupling. Forn≧4 rigid behavior prevails at all temperatures; similarly only rigid behavior is found for strongly anisotropic systems for alln. The thermodynamic stability of the system is investigated by evaluating the contribution of ring diagrams for the casen=1. It is thus shown that under constant hydrostatic pressure a first-order transition occurs in both isotropic and anisotropic systems, and the corresponding equations for the transition temperature and the value of the order parameter atT c are derived.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01301523
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