Papers by Author: Roman Kolano

Abstract: The magnetocaloric effect in La0.6Ca0.4MnO3 manganite has been investigated. The isothermal magnetization versus applied magnetic field at various temperatures in the vicinity of Curie temperature was measured, and the temperature dependence of magnetic entropy change was determined using Maxwell’s relation. This value is comparable to that in Gd. Nevertheless, the relative cooling power of La0.6Ca0.4MnO3 was shown to be considerably lower than that of Gd. The experimental results have been analyzed in frames of a phenomenological statistical model. This model considers explicitly Jahn-Teller interactions and allows prediction of the field dependences of the magnetic entropy change and the relative cooling power.

Abstract: Paper presents the results of investigation on functional characteristics of magnetoelastic compressive force sensor utilizing two Fe81Si4B15 amorphous alloy ring-shaped cores. Uniform distribution of stresses in one of two cores was achieved owing to special non-magnetic backings. Signal from sensing coils of cores was connected to differential amplifier, whereas sine wave voltage signal was applied to magnetizing circuit. High stress sensitivity of developed sensor was indicated together with expected reduction of temperature sensitivity of magnetoelastic sensor. These results confirm, that differential configuration of magnetoelastic sensor is suitable for practical application in sensors development.