Temperature-induced changes in the EPR spectrum of the magnetic center in kaolin.
Studies of kaolin have revealed an effect characterized by an unusual temperature-induced change of the EPR spectrum of the Fe3+ ion, which is the magnetic probe in kaolin-clay. At low temperature (T=4.2 K) a resonance line with an effective g-value g1=4.13 +/- 0.16 is observed. At high temperature (T=288 K) one observes a resonance line with the effective g-value g2=2.15 +/- 0.1. The transition from the low- to high-temperature spectrum is gradual and it is accompanied by a redistribution of the absorption intensity. The observed properties of the temperature dependence of the EPR spectrum are characteristic of systems with a multiminimum potential.
Vasyukov
Vladimir N
VN
Donetsk Physical-Technical Institute of the National Academy of Sciences of Ukraine, 83114 Donetsk, Ukraine.
Shapovalov
Vladimir V
VV
Schwarz
Steven A
SA
Rafailovich
Miriam H
MH
Sokolov
Jonathan C
JC
Shapovalov
Vladimir A
VA
Beloshenko
Viktor A
VA
D004578:Electron Spin Resonance Spectroscopy; D007616:Kaolin / Q000737:chemistry*; D008280:Magnetics; D013696:Temperature
D007616:Kaolin