Medidas de tempos de relaxação spin-rede em cristais mistos de halogenetos alcalinos. / Spin-lattice relaxation measurements on mixed crystals of alkali halides.

AUTOR(ES)
DATA DE PUBLICAÇÃO

1983

RESUMO

Using magneto-optic techniques we have studied the ground state spin- lattice relaxation times (T1) of Fcenters in mixed Alkali Halide cristals (KCl-KBr). We describe a computer assisted system to optically measure short relaxation times (~1mS). The technique is based on the measurement of the Magnetic Circular Dicroism (MCD) presented by F centers. We obtained the T1 magnetic field dependency at 2 K up to 65 kGauss), as well as the MCD spectra for different relative concentration at the mixed matrices. The theory developed by Panepucci and Mollenauer for F centers spin-lattice relaxation in pure matrices was modified to explain the behavior of T1 in mixed cristais. The Direct Process results (T~2.0 K) compared against that theory shows that the main relaxation mecanism, Up to 25 kGauss, continues to be phonon modulation of the hyperfine interaction between Felectrons and surrounding nuclei.

ASSUNTO(S)

dicroismo circular circular dichroism relaxation magneto óptica relaxação magneto-optics

ACESSO AO ARTIGO

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