Room temperature magnetoresistance and exchange bias in “314-type” oxygen-vacancy ordered SrCo0.85Fe0.15O2.62

Abstract

Herein, we report the magneto-transport and exchange bias effect in a "314 -type" oxygen -vacancy ordered material with composition SrCo 0.85 Fe 0.15 O 2.62 . This material exhibits a ferrimagnetic transition above room temperature, at 315 K. The negative magnetoresistance starts to appear from room temperature (-1.3 % at 295 K in 70 kOe) and reaches a sizable value of 58 % at 4 K in 70 kOe. Large exchange bias effect is observed below 315 K when the sample is cooled in the presence of a magnetic field. The coexistence of nearly compensated and ferrimagnetic regions in the layered structure originate magnetoresistance and exchange bias in this sample. The appearance of a sizable magnetoresistance and giant exchange bias effect, especially near room temperature indicates that "314-type" cobaltates are a promising class of material systems for the exploration of materials with potential applications as magnetic sensors or in the area of spintronics.Transition metal oxides (TMOs) with strong electron correlations are a fascinating class of material systems exhibiting exotic electronic and magnetic complexity which can be turned into promising technological applications. Example includes high-T c superconductivity (SC) in cuprates, 1 colossal magnetoresistance (CMR) in manganites 2 and multiferroicity in bismuth compounds. 3 For the practical utilization of these properties, a transition temperature near or above room temperature (RT) is usually required. In this context, ferrimagnetic TMOs with transition higher than RT have attracted considerable interest in recent times. For instance, Sr 2 FeMoO 6 and Sr 2 FeReO 6 materials having ferrimagnetic transition higher than 400 K show room temperature magnetoresistance. 4-6 Transition-metal-only ferrimagnetic double perovskites with chemical composition Mn 2 BReO 6 (B = Fe and Mn) show a new way to control magnetoresistance in spintronic materials. 7-9 The non-stoichiometric Ba 2 Fe 1.12 Os 0.88 O 6 compound (ferrimagnetic transition temperature T c = 370 K) shows the appearance of exchange bias effect near room temperature. 10 In this letter, we report the room temperature exchange bias effect and magnetoresistance for "314-type" cobaltate with composition SrCo 0.85 Fe 0.15 O 2.62 . The oxygen deficient "314-type" compounds crystallize in a tetragonal symmetry, space group I4/mmm with a 2a p × 2a p × 4a p (a p = lattice parameter of the cubic perovskite) type unit cell and show the appearance of above RT ferrimagnetism. [11][12][13][14][15][16] A pure phase polycrystalline sample of SrCo 0.85 Fe 0.15 O 2.62 was prepared by standard solid-state reaction method as reported previously. 16 The sample was characterized by X-ray powder diffraction (XRD) at room temperature (RT), performed in a Panalytical a)

Magnetism and Exchange Bias Properties in Ba2ScRuO6

“…The small observed hysteresis could be due to frustration in the structure. In recent times, there has been significant interest in exploring and understanding the effects of exchange bias (EB) in structurally inhomogeneous systems with various combinations of magnetic cations [30][31][32][38][39][40][41]. In the exchange bias effect, the field-cooled (FC) M-H loops show a shift along the magnetic field axis, and this is used in several technological applications, such as magnetic recording read heads [42], random access memories [43], and other spintronics devices [44,45].…”

Magnetization reversal, giant exchange bias effect and magnetoresistance in oxygen vacancy ordered Sr4Fe3CoO11

“…Recently, the complex magnetic materials have attracted remarkable interest for exploring the exchange bias effect (EB) [4,[23][24][25][26]. The EB phenomenon is generally demonstrated as a shift [27] in the isothermal magnetization loop with respect to the field axes.…”

“…Strongly correlated transition metal oxide (TMOs) material systems has attracted widespread attention as a plethora of exotic phenomena such as high-temperature superconductivity (SC, cuprates) [1], colossal magnetoresistance (manganites) [2], exchange bias [3,4] and multiferroicity (bismuth compounds) [5] arises from correlated electron physics in 3d TMOs. Indeed, the strong correlation among electrons is a connecting feature of TMOs exhibiting extraordinary electronic and magnetic properties, and that can develop into a promising technological application (such as in electronics and spintronic field).…”

Manipulating exchange bias in Co/IrMn films by surface acoustic wave

“…The magnitude of the EB field (H EB ) is not only related to the specific materials but also to other parameters of the sample, such as the thickness of the FM (t FM ) layer [8,9], the thickness of the AFM layer [9], and the grain size [10], etc. In addition, external conditions, such as annealing temperature [11], test temperature [12][13][14][15][16], ion irradiation, and even the number of measurements [16][17][18] (training effects exist in some EB samples) are also proven to influence the H EB .…”