Published February 1986 | Version v1
Journal article Metadata-only

X-ray induced valence change in the V3+:MgO system

Creators

  • 1. Instituto Militar de Engenharia, Rio de Janeiro (Brazil)

Description

The V3+-> V2+ transformation has been observed by electron spin resonance (ESR) in polycrystalline samples of magnesium oxide irradiated with X-rays. At low doses, the concentration of V2- centers increases linearly with the irradiation time; at high doses, the V2+ concentration saturates with a value that is much smaller than total vanadium concentration in the sample. The V2+ centers are unstable; at room temperature, their decay is characterized by two time constants, one of 16 days and the other of 228 days. (Author)

Abstract (Portuguese)

Estuda-se a transformacao V3+->V2+ atraves de ressonancia paramagnetica eletronica, em amostras policristalinas de oxido de magnesio irradiado com raios-x. Em baixas doses a concentracao de centros V2+ aumenta linearmente com o tempo de irradiacao e em doses altas a concentracao de v2+ satura em um valor que e muito menor do que a concentracao total de vanadio na amostra. Os centros V2+ sao instaveis; a temperatura ambiente seu decaimento e caracterizado por dois tempos constantes, um de 16 dias e outro de 228 dias. (C.B.)

Additional details

Additional titles

Original title (Portuguese)
Mudanca de valencia induzida por raios-x no sistema V

Publishing Information

Journal Title
Ceramica (Sao Paulo)
Journal Volume
32
Journal Issue
193
Series
Ceramica (Sao Paulo).
Journal Page Range
27-30
ISSN
0366-6913
CODEN
CMCAA

INIS

Country of Publication
Brazil
Country of Input or Organization
Brazil
INIS RN
18008331
Subject category
S38: RADIATION CHEMISTRY, RADIOCHEMISTRY AND NUCLEAR CHEMISTRY;
Descriptors DEI
ELECTRON SPIN RESONANCE; MAGNESIUM OXIDES; THERMONUCLEAR REACTOR MATERIAL; VANADIUM IONS; X RADIATION
Descriptors DEC
ALKALINE EARTH METAL COMPOUNDS; ATOMIC IONS; CHALCOGENIDES; CHARGED PARTICLES; ELECTROMAGNETIC RADIATION; IONIZING RADIATIONS; IONS; MAGNESIUM COMPOUNDS; MAGNETIC RESONANCE; MATERIALS; OXIDES; OXYGEN COMPOUNDS; RADIATIONS; RESONANCE