Correlation between the negative magnetoresistance effect and magnon excitations in single-crystalline CuCr1.6V0.4Se4 |
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| Authors: | E Malicka D Skrzypek AW Pacyna D Badurski A Wa?kowska |
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| Institution: | 1. University of Silesia, Institute of Chemistry , ul. Szkolna 9, 40-006 Katowice, Poland;2. University of Silesia, Institute of Physics , ul. Uniwersytecka 4, 40-007 Katowice, Poland;3. The Henryk Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences , ul. Radzikowskiego 152, 31-342 Kraków, Poland;4. Institute of Low Temperature and Structure Research, Polish Academy of Sciences , ul. Okólna 2, 50-950 Wroc ?aw, Poland |
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| Abstract: | Structural, electrical and magnetic measurements, as well as electron spin resonance (ESR) spectra, were used to characterise the single-crystalline CuCr1.6V0.4Se4 spinel and study the correlation between the negative magnetoresistance effect and magnon excitations. We established the ferromagnetic order below the Curie temperature T C ≈ 193 K, a p-type semiconducting behaviour, the ESR change from paramagnetic to ferromagnetic resonance at T C, a large ESR linewidth value and its temperature dependence in the paramagnetic region. Electrical studies revealed negative magnetoresistance, which can be enhanced with increasing magnetic field and decreasing temperature, while a detailed thermopower analysis showed magnon excitations at low temperatures. Spin–phonon coupling is explained within the framework of a complex model of paramagnetic relaxation processes as a several-stage relaxation process in which the V3+ ions, the exchange subsystem and conduction electron subsystem act as the intermediate reservoirs. |
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| Keywords: | magnetoresistance spin waves thermoelectric effects electron spin resonance |
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