Optically induced variation of magnetic and photoelectric properties of ferrites

Abstract

The laser irradiation of ferrites in a dc magnetic field at room temperature leads to a significant change of their residual magnetization and photovoltaic response, both in magnitude and the symmetry with respect to a magnetic field. The photovoltage also acquires a nonlinear field dependence. The variation in the properties is retained by the samples for a long time. This lifetime strongly depends on the wavelength of the laser light. Photoinduced effects are connected with photomagnetization (PM) which arises during irradiation. The PM was directly measured with a magnetometer on single crystal Mn1−xZnxFe2O4 ferrites (bulk) with x=0.09 (1) and 0.56 (2) as well as on MeFe2O4 ferrite films with Me=Mn (3), Ni (4), and Co (5). The effect might be useful for optical recording.

Temperature Frequency Characteristics of Charge Transition in the Li0.5Fe2.4Ti0.1O4 Non-stoichiometric System

“…In case of the intermittent mechanism the conductivity increases compared to zone conductivity, which does not depend upon the external field frequency up to f =10 9 10 11 Hz frequency [4,19].…”

Photo-induced bias of the hysteresis loop in ferrites at room temperature with long-time memory

“…Ferrites are the AFM semiconductors, where charge carriers are small polarons with a low mobility (10 À2 cm 2 /V s), which exponentially grows with temperature [30].…”

Photochromism and Photomagnetism in 1,4-bis(4,5-diphenyl-imidazolyl)benzene Chromophores: Water Assisted π-stacks for the Generation of Stable Free Radicals in Solid State

“…[12][13][14][15] This phenomenon was observed for many years in metals (Cu, Al) and metal oxides (ferrites, garnets), after that Prussian Blue analogs (PABs) was introduced by Hashimoto and coworkers as an efficient photomagnet in late 90s. [16][17][18] More recently, a new class of inorganic-organic hybrid material had been developed by incorporating photochromic moiety into 3d-4f heterobimetallic complexes that show photomagnetism at room temperature. [19,20] The photomagnetism was shown to originate due to photoinduced electron transfer (PET) from electron-rich (18-crown-6) or electron-deficient (viologen derivatives) organic moieties to redox active metal ions.…”