Electronhyphen;electron double resonance study of trapped electrons in ggr;hyphen;irradiated 2hyphen;methyltetrahydrofuran glass: Magnetic energy transfer between two different spin systems

摘要

Electronhyphen;electron double resonance (ELDOR) of trapped electrons and radicals in ggr;hyphen;irradiated 2hyphen;methyltetrahydrofuran (MTHF) glass at 77deg;K was investigated. Magnetic energy pumped into the radical spin system is transferred to the trapped electron spin system to partially saturate it. The cross saturation mechanism is consistent with dipolar cross relaxation in which a radical spin flips down and an electron spin flips up. Analysis of the rate of spin relaxation shows that the reciprocal ELDOR reduction is linear with pumping microwave power with an intercept which gives the ratio of the crosshyphen;relaxation time to the electron spinhyphen;lattice relaxation time. The experimental data are found to fit this relationship. This ratio of relaxation times is of the order of 0.5 while the relaxation times themselves are in the 10minus;4hyphen;sec range. The observation of cross relaxation in this system supports the concept that the trapped electron and radical are spatially correlated in ggr;hyphen;irradiated MTHF.