Spin-pairing transition

Shock-wave experiments causing phase changes in wiistite, Fe094O, and Fe203 have also produced controversial evidence for spin-pairing transitions in iron cations (Jeanloz and Ahrens, 1980 Jackson and Ringwood, 1981 Goto et al., 1982 Syono etal., 1984). 

Calculated spin-pairing transition pressures in the Mantle... 

Goto, T., Sato, J. Syono, Y. (1982) Shock-induced spin-pairing transition in Fe203 due to the pressure effect on the crystal field. In High-Pressure Research in Geophysics. (S. Akimoto M. H. Manghani, eds D. Reidel Publ. Co., Dortrecht), pp. 595-609. 

Fe(NO) 2,2 -OC6H4 CH=N(CH2)2 N=CH CgH O- 300- 100 at wl80 K spin-free, spin-paired transition with phase change 65E2, Fig. 155... 

The QS arises from the interaction between the nuclear quadrupole moment and the nonspherical component of the electronic charge distribution described by its effective electric field gradient (EFG) in a simplified model [19,28]. The effective electric field gradient is dramatically reduced due to the spin-pairing transition. The electron shell of the high-spin Fe " " ions in the octahedral coordination is spherically asymmetric with S = 2 and t e t, whereas Fe " " ions in the low-spin state are more spherically symmetric with S = 0 and (the arrows indicate spin up or spin down whereas... 

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