Antiferromagnetic ground state

A three-dimensional set of intermolecular interactions is further confirmed by the observation of a transition to an antiferromagnetic ground state in both radical complexes, at a Neel temperatures of 8 (Mo) and 4.5 K (W), in accordance with the difference of Curie-Weiss temperatures between both complexes. Note also the spin-flop field in the antiferromagnetic state, found at 5.5 kG in [Cp M(dmit)2] and at 8 kG in [Cp W(dmit)2] , a consequence of the stronger spin orbit coupling in the latter. 

K. The stable antiferromagnetic ground state was also evident from the negative Weiss constant of —14 K and the monotonically increasing magnetization curve with a value of 2.8 p.b/Eu at 2 K and 5.5 T.151 Eu Mossbauer spectroscopic studies confirmed the divalent nature of europium in EuAuPb with an isomer shift value of —10.9 mm/s at 78 K. Line broadening in the Mossbauer spectra occurred around... 

In the general case the proposed form of the wave function corresponds to the MP form but with matrices of infinite size. However, for special values of parameters of the model it can be reduced to the standard MP form. In particular, we consider a spin-1 ladder with nondegenerate antiferromagnetic ground state for which the ground state wave function is the MP one with 2x2 matrices. This model has some properties of ID AKLT model and reduces to it in definite limiting case. 

The spin density wave (SDW) is a 2kF instability due to spin-spin interactions and the ground state has no lattice distortion. s is typical of an antiferromagnetic ground state and therefore anisotropic below the transition temperature, Tc. Antiferromagnetic resonance (AFMR) may be a good technique to characterize this transition. A particular characteristic is that the Tf1 NMR relaxation rate diverges at Tc. 

In the exited free paramagnetic state, Jy is zero. Hence, the energy difference, AE, between the paramagnetic state and the antiferromagnetic ground state amounts to... 

The temperature dependence of the susceptibility of UHg2 was studied by Misiuk et al. (1972c). It exhibits a sharp maximum located at 70 K, indicating an antiferromagnetic ground state. The maximum in d(xT)/dT shows the transition... 

Antiferromagnetic ground state with TN = 7 K and no specification of the crystal structure (Troc et al. 1985). 

An antiferromagnetic ground state of UCr2Si2 is reported by Buschow and de Mooij (1986) on the basis of magnetic susceptibility measurements. Above TN, CW behaviour with the parameters given in table 4.6 is approximately obeyed. 

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