Superparamagnetic and ferrimagnetic nanoparticles in glass matrix

Faraday rotation (FR) spectral, field, and temperature dependencies in oxid e glasses with small additions of paramagnetic elements are investigated. F ormation of ferrite nanoparticles in amorphous glass matrices is revealed b y X-ray diffraction. Particles have crystal structure similar to spinel str ucture, their dimensions are about 10-24 nm. The FR field dependencies are typical for ferrimagnetic or superparamagneti c substances depending on particle size. Strong FR increase at the samples cooling (more than twice for some samples) in the temperature interval 105- 273 K is observed. (C) 2001 Elsevier Science B.V. All rights reserved.