Magnetic field cycling effect on the non-linear current-voltage characteristics and magnetic field induced negative differential resistance in α-Fe1.64Ga0.36O3 oxide

Abstract

We have studied current-voltage (I-V) characteristics of α-Fe1.64Ga0.36O3, a typical canted ferromagnetic semiconductor. The sample showed a transformation of the I-V curves from linear to non-linear character with the increase of bias voltage. The I-V curves showed irreversible features with hysteresis loop and bi-stable electronic states for up and down modes of voltage sweep. We report positive magnetoresistance and magnetic field induced negative differential resistance as the first time observed phenomena in metal doped hematite system. The magnitudes of critical voltage at which I-V curve showed peak and corresponding peak current are affected by magnetic field cycling. The shift of the peak voltage with magnetic field showed a step-wise jump between two discrete voltage levels with least gap (ΔVP) 0.345(± 0.001) V. The magnetic spin dependent electronic charge transport in this new class of magnetic semiconductor opens a wide scope for tuning large electroresistance (∼500-700%), magnetoresistance (70-135 %) and charge-spin dependent conductivity under suitable control of electric and magnetic fields. The electric and magnetic field controlled charge-spin transport is interesting for applications of the magnetic materials in spintronics, e.g., magnetic sensor, memory devices and digital switching.

Doping of Ga in antiferromagnetic semiconductor α-Cr2O3 and its effects on magnetic and electronic properties

“…The enhanced ferromagnetism and magnetic exchange bias effect has provided the experimental evidence of modified spin order (core-shell structure) and magnetic anisotropy in AFMNP [2][3][4]. From application point of view, increase of ferromagnetic (FM) component in AFMNP is important for the development of magnetic semiconductor with reasonably large ferromagnetic moment, tunable band gap in the UV-Vis range of light and electrical field controlled electronic properties at room temperature [8][9][10][11][12].…”

“…structure by alloying of a-Fe 2 O 3 and β-Ga 2 O 3 has modified optical band gap, ferromagnetic, electronic and magneto-electronic properties [9,[11][12].…”

Non-equilibrium character of resistive switching and negative differential resistance in Ga-doped Cr2O3 system

“…1(g) shows that I-V curves in the low voltage regime of the S1 segment and entire S2 segment followed power law ( ~ ) with exponent m in the range 1.05-2.37 and 0.92-1.13, respectively. For trapping free SCLC mechanism in solid state devices, the exponent is 2; otherwise, exponent values can be less than 2 [11][12]30]. This means the I-V curve in the S2 segment does not follow a typical SCLC mechanism.…”

“…The thin films of transition metal oxides, e.g., Cr 2 O 3 [7], Ga 2 O 3 [8][9], Al 2 O 3 [10], Fe 2 O 3 [11], Ga-doped Fe 2 O 3 [12], Ba 0.7 Sr 0.3 TiO 3 [13], NiO [14], TiO 2 [15][16], and SiO 2 [17] have shown different types of resistive switching, i.e., unipolar, bipolar or abnormal nature.…”

Negative Pulse and Compliance Current Dependent Negative Differential Resistance in ZnO/Nb:SrTiO3 Heterojunctions

“…[6][7][8][9][10][11] The NDR feature has been found to be strongly dependent on temperature, [7,10] moisture, [8] bias voltage, [12][13][14] air exposure, [15] metal ion implantation, [16] edge fluorination, [17] ferroelectric polarization switching, [18,19] light irradiation, [20] and magnetic field. [21] In our previous reports, temperature-and positive pulse-dependent NDR accompanying RS was studied. [22] The oxygen vacancies are supposed to be ionized under a positive pulse, which will drift and lead to NDR under a negative bias.…”