Colossal magnetoresistance

About: Colossal magnetoresistance is a research topic. Over the lifetime, 3658 publications have been published within this topic receiving 130104 citations.

Magnetotransport and rectifying properties in La0.67Ca0.33MnO3/yttrium-stabilized zirconia/Si heterojunction

Abstract: A heterojunction has been fabricated by growing a La067Ca033MnO3 film on silicon with a buffer layer of yttrium-stabilized zirconia (YSZ) The current-voltage measurement shows that it is a diode with a good rectifying property At low positive bias voltage, temperature dependence of the junction resistance shows a peak at a certain temperature, which shifts to low temperatures when the voltage is increased from 03Vto07V This behavior is quite different from the previous reports on p-n junctions composed of manganites and Nb-doped SrTiO3 The heterojunction shows remarkable magnetoresistance for both positive and negative biases The results were discussed by considering the depletion layers in both La067Ca033MnO3 and Si, and the tunneling through YSZ This work shows the potential application of integrating manganite-based devices and semiconductor circuits

Effect of ferroelectric layers on the magnetocapacitance properties of superlattices-based oxide multiferroics

Abstract: A series of superlattices composed of ferromagnetic La0.7Ca0.3MnO3 (LCMO) and ferroelectric/paraelectric Ba1−xSrxTiO3 (0⩽x⩽1) were deposited on SrTiO3 substrates using pulsed laser deposition. Magnetotransport properties of the films reveal a ferromagnetic Curie temperature in the range of 145–158K, and negative magnetoresistance as high as 30%, depending on the type of ferroelectric layers employed for their growth (i.e., “x” value). Ferroelectricity at temperatures ranging from 55Kto105K is also observed, depending on the barium content. More importantly, the multiferroic nature of the film is determined by the appearance of negative magnetocapacitance, which is maximum around the ferroelectric transition temperature (3% per tesla). These results are understood based on the role of the ferroelectric/paraelectric layers and strains in inducing the multiferroism.

Large magnetoresistance tunnelling through a magnetically modulated nanostructure

Abstract: Based on a combination of an inhomogeneous magnetic field and a two-dimensional electron gas, we have constructed a giant magnetoresistance nanostructure, which can be realized experimentally by the deposition of two parallel ferromagnetic strips on top of a semiconductor heterostructure. We have theoretically studied the magnetoresistance for electrons tunnelling through this nanostructure. It is shown that there exists a significant transmission difference between the parallel and antiparallel magnetization configurations, which leads to a large magnetoresistance. It is also shown that the magnetoresistance ratio strongly depends not only on incident electronic energy but also on the ferromagnetic strips, and thus a much larger magnetoresistance ratio can be obtained by properly fabricating the ferromagnetic strips in the system.

A-site ordering versus electronic inhomogeneity in colossally magnetoresistive manganite films.

Abstract: Epitaxial La(3/4)Ca(1/4)MnO3/MgO(100) (LCMO) thin film shows an unusual rhombohedral (R-3c) structure with a new perovskite superstructure at room temperature due to the CE-type ordering of La and Ca with modulation vector q=1/4[011]. A-site ordered film was found to be electronically homogeneous down to the 1 nm scale as revealed by scanning tunnelling microscopy/spectroscopy. In contrast, orthorhombic and A-site disordered LCMO demonstrate a mesoscopic phase separation far below the Curie temperature (TC). Unique La/Ca ordering compensates the cation mismatch stress within one supercell, a(S) approximately 1.55 nm, and enhances the electronic homogeneity. The phase separation does not seem to be a unique mechanism for the colossal magnetoresistance (CMR) as very large CMR approximately 500% was also observed in A-site ordered films.