Cu spin structures

Cu ordering in Cm2Cu04 has not been studied yet, but the Cu spin structure is not expected to be different from other R2CUO4 compounds. 

Cu spin structure is different from all other related materials. In this system, the magnetic unit cell is doubled along the c-direction. 

Let us examine now the mechanism of the interchain coupling. Owing to the relative positions of two adjacent chains, the dominant interchain interactions are Cu(II)Cu(II) and Mn(II)Mn(II). If these interactions are antiferromagnetic, then the spin structure will be ... 

As mentioned earlier, the linear exchange interaction between Cu layers cancels due to the bet symmetry, and the actual spin structure is then a result of a delicate balance of superexchange, spin-orbit, and Coulomb exchange interactions (Yildirim et al. 1994, 1996). In the absence of the R ions, quantum fluctuations would be expected to yield the collinear magnetic structure (Yildirim 1999) and this may indeed be the case for the Sr2Cu02Cl2 material (Yildirim et al. 1998). However, this leaves unexplained the... 

Fig. 12.21 The EPR spectrum of 5-chlorosalicylaldoxinecopper(ll). In this complex there are two N atoms, each with spin 1, coordinated to the copper, so that the resultant N spin can be 2, 1, 0, -1 or -2. It follows that a five-line peak structure is expected. The Cu spin of I gives rise to a four-line structure 2- 2. - ) and so the spectrum is interpreted as indicated. Clearly, the unpaired electron interacts with both copper and nitrogen nuclei. This spectrum is presented in derivative form, the normal presentation for EPR spectra.

---