Pressure dependence of the magneto-transport properties in Fe/MgO granular systems

0424315 - FZÚ 2014 RIV KR eng J - Journal Article
García-García, A. - Algarabel, P.A. - Pardo, J.A. - Arnold, Zdeněk - Kamarád, Jiří
Pressure dependence of the magneto-transport properties in Fe/MgO granular systems.
Journal of the Korean Physical Society. Roč. 62, č. 10 (2013), s. 1458-1460. ISSN 0374-4884. E-ISSN 1976-8524
Institutional support: RVO:68378271
Keywords : granular materials * tunneling magnetoresistance * hydrostatic pressure
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 0.425, year: 2013

The effect of hydrostatic pressure at room temperature on the resistance and magnetoresistance(MR) of a discontinuous metal-insulator multilayer (DMIM) of nominal composition [Fe(tFe=0.7nm)/MgO(tMgO=3nm)]15 has been studied. The resistivity of the DMIM,ρ, decreases linearlywith pressure indicating an increase in conduction via tunneling effect. The value of coefficient(1/ρO)dp/dP=–3.9×10-2kbar-1is higher than reported values in other granular films implying that the electronic state of the DMIM is close to the iron percolation threshold. At the maximum applied magnetic field (3 kOe) the MR ratio increases from 0.6% at ambient pressure to 1.1% at 7 kbar. This result can be explained by a reduction of the tunnel barrier width induced by the hydrostatic pressure.
Permanent Link: http://hdl.handle.net/11104/0230392