3DXY model

The critical behaviours of higher order satellites near a continuous phase transition are of particular interest, as they provide the opportunity to study the crossover exponents of the respective symmetry breaking perturbations in the spin Hamiltonian. Each order of satellite has an associated order parameter critical exponent given by / = 2 - a -where a is the specific heat exponent, and crossover exponent As an example, if the transition is described by the 3DXY model, then the exponent 2 measures the crossover caused by a perturbation of uniaxial symmetry. For this model, theory predicts that = o P, with... 

Fig. 4.7 Trinuclear model complex with C2v symmetry. TM is one of the transition metals with an incomplete d electronic configuration with high spin coupling. The orbitals in the lower part are (ai), (bi), 3dxz (b ), 3d 2 yi (a ) and 3dxy (02) and are ordered from left to right by...

The grey-filled squares are values from numerous e )eriments (tabulated in [48]). The square wiUi tJie large error bar (x-ray scattering experimental result of Bouwman Mid de Jeu [51]) with errors modified due to a reconsideration of die fitting procedure. The black circles with errors are from recent scattering studies with mosaicity corrections taken into account[50]. Bodi die 3DXY and the tricritical models predict isotropic exponents (A, = 1). Strong anisotropy would predict = 2... 

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