Manganite-based devices: opportunities, bottlenecks and challenges

Abstract

Since the rejuvenation of interest in the rare earth manganites owing to their potential use as magnetoresistive sensors, there has been adequate research to arrive at some evaluation of the potential for these materials in a variety of technologies that would use the peculiar properties of these materials. The magnetic field sensitivity of the transport properties, the strong metal insulator transition at the Curie temperature, the electric field polarizability of the material and its subsequent effect on the transport properties, the half metallicity of the electronic bands, etc., are properties of the rare earth manganites that could be exploited in a variety of devices. In this review we explore the various interesting technological avenues that are being pursued and address the uniqueness of the material that may enable a given technology as well as the various bottlenecks that will have to be overcome in order to successfully compete with the existing technologies. As is the case with many emerging materials technologies, the devices also serve as a vehicle for further understanding of the fundamental mechanisms behind the basic properties of the materials.

A-site deficiency effects on the structure, magnetic and transport properties of Pr0.6−x□xSr0.4MnO3 (0≤x≤0.2) perovskite manganite

“…Doped perovskite manganites R 1−x A x MnO 3 where R and A are respectively trivalent rare earth and divalent alkali-earth elements have attracted considerable attention during the last decade for their interesting physical properties and especially for the colossal magnetoresistance CMR that they exhibit and which is promising for several magnetic applications [1,2]. It is well accepted that the substitution of the rare earth element by the divalent alkali metal leads to a mixed valence Mn 3+ /Mn 4+ state and induces a transition from paramagnetic-insulator to a ferromagnetic-metallic phase.…”

Structural and magnetic properties of La0.6−x□xCa0.4MnO3 (0≤x≤0.2) perovskite manganite

“…Since the discovery in 1994 of colossal magnetoresistance (CMR) effects in perovskite manganese oxides with general formula Ln 1−x A x MnO 3 (Ln is a rare earth element and A is a divalent alkali earth element), these compounds have attracted considerable attention due to their rich physical properties and their high potential for magnetic applications [1][2][3]. It is well accepted that the substitution of the rare earth element by a divalent alkali metal leads to a mixed valence Mn 3+ /Mn 4+ state and induces a transition from paramagnetic-insulator to ferromagnetic-metallic phase.…”

Annealing effect on transport properties of Nd0.67Sr0.33MnO3 thin films

“…Magnetoresistance measurements on N1a1 show considerable low temperature MR (38% at 20 K under a 6.4 T field) (figure 7a and table 5) comparable to those seen in polycrystalline samples [30]. However unlike polycrystalline samples MR(À) is seen to be linear at low temperatures.…”

“…MR(À) for single crystals is found to be linear at low temperatures [29]. In polycrystalline bulk and thin films the observed low temperature MR (LTMR) is very high (30-40%) MR for´Ì ¼ ½ Ì ) [30]. MR(À) for polycrystalline materials is essentially non-linear with a much sharper response to small field changes (i.e.…”

“…MR(À) for polycrystalline materials is essentially non-linear with a much sharper response to small field changes (i.e. large low field MR) [29,30].…”