Equation Bleaney-Bowers

FIGURE 3.3 Temperature dependence of yT (a), y (b), and 1 /y (c) for a ferromagnetically, antiferromagnetically, and uncoupled spin-1/2 dimer as calculated by the Bleaney-Bowers equation (Equation 3.12). 

S2 possesses the eigenvalues S(S + 1). For a spin-1/2 dimer (S can be 0 or 1), the same values are obtained from the derivation of the Bleaney-Bowers equation. For spin systems in an external magnetic field, the Zeeman operator Hmag = -g/ BB S accounts for Zeeman splitting. The isotropic Heisenberg Hamiltonian for multiple spin centers can be expanded by adding the individual coupling pairs ... 

Fig. 356. KCuBr3. Temperature dependence of Xa- The solid curve was calculated from the modified Bleaney-Bowers equation...

Xmax at T=19 K, antiferromagnetic interaction suggested probably polymeric magnetism fitted to the Ising model (J/hc= —14cm" , g=1.95) and to the Bleaney-Bowers equation for coupled pairs (2J/hc= —21 cm" g = 1.85)... 

Gouy probably antiferromagnetic J calculated according to Bleaney-Bowers equation J/hc=147 cm , g=1.99,... 

V0 2,4,2 -0(CH3)C6H3 CH=N CgH4 O-. Temperature dependence of x m- Experimental curve with allowance for 1 % monomer (1). Theoretical curve, 1 % monomer (2), fitted according to modified Bleaney-Bowers equation... 

V0 2,4, 2 -0 CgH4 - CH=N C H3(N02)0-. Temperature dependence of Experimental curves (J) with allowance for 2% monomer (3) 4% monomer. Theoretical curves magnetism fitted according to modified Bleaney-Bowers equation... 

The solid curves represent the Bleaney-Bowers equation [74T17],... 

NCS)3 ),J/hc= - 87.5 cm- J /hc= -25 cm , g=2.15, iV =45 10- emu/mol. Temperature dependence of Xm-Solid lines theoretical curves based on the tetranuclear cluster using the parameters given above. Broken line theoretical curve based on the Bleaney-Bowers equation using the parameters g=l,99, = 60 10 emu/mol,... 

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