Medidas magneto-óticas de tempos de relaxação Spin-Rede em KBr e nos halogenetos de Na e Cs e estudo de Dicroismo Circular Magnético do Ion Co++ em KCl. / Magneto-optical measurements of spin-lattice relaxation times in KBr, Na and Cs halides and Magnetic Circular Dichroism of Co++ dopped KCl.

AUTOR(ES)
DATA DE PUBLICAÇÃO

1977

RESUMO

In this work we describe a Magnetic Circular Dicroism Spectrometer wich was used in the following experiments: 1) We measured the spin-lattice relaxation time (T1) for F centers in NaCl, NaBr, CsBr and CsCl, at 1,8°K in magnetic fields up to 15000Gs. We verified the suitability of the theory of ref.(O8) to explain the differences observed for halides of differents alkali ions as well as for different structures. This proves that the hyperfine interaction is the most important mechanism for this kind of centers. We also verified that, for temperatures between 6°K and l5°K, T1, the T1 experimental values fits the theory of ref.(21) reasonably well ,for F centers in KBr. This theory is an extension of that of ref.(8). 2) We obtained the MCD spectra for KCl: Co++ and CaF2: Co++ in different magnetic fields up to 56KGs, and in temperature range between 1,8 °K and 4,2°K. Our results are consistent with the assumption that Co++ centers are intersticial in KCl lattice.

ASSUNTO(S)

cobalto halogenetos alkali halides relaxation times cobalt magnetic circular dichroism spin-lattice dicroismo circular magnético tempos de relaxação spin-red alcalinos

ACESSO AO ARTIGO

Documentos Relacionados