Magnetotransport at Domain Walls inBiFeO3

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

“…Most striking feature is the magnetic field induced NDR effect. In literature, various models have been discussed to realize the origin of NDR effect, e.g., Joule heating induced phase segregation 21,32 and charge order state, 28,29 space charge limited current (SCLC) mechanism, 14,16,17,22 spin filter and spin valve effect, 25 magnetic domain effect, 19 and charge-spin accumulation and transfer across non-magnetic metal electrode-magnetic semiconductor junctions. [13][14][15]33 The ferromagnetic loop in our sample does not show any meta-magnetic phase transition, 6 which generally marks for the occurrence of charge ordered structural phase segregation in manganite systems.…”

“…Such increase of resistance can be attributed to spins scattering effect at the interfaces or grain-boundaries of the magnetic material. 16,19 Space charge also exhibited a great impact on the large positive MR in non-magnetic material. 17 However, the nature of the MR(%) curves in our sample with H at selected voltages is different from that observed due to space charge effect.…”

“…[13][14][15]18 The I-V characteristics under magnetic field are also useful to extract the information of the effects of magnetic domain wall motion and magnetic domain rotation on the current flow mechanism in FMSUT. 1,19 To our knowledge, there is no work which dealt magnetic field controlled electronic properties for metal doped hematite system, despite the fact that such system has a bright future for the applications in multifunctional devices. 20 Our earlier works 5,6 have discussed the canted ferromagnetic properties in Ga doped hematite system.…”

Electric field control of ferromagnetism using multi-ferroics: the bismuth ferrite story

“…In order to truly confirm that there is enhanced conduction through the domain walls, we carried out macroscopic transport measurements through an array of such domain walls. Macroscopic magnetotransport studies ( figure 1c, d) show the existence of a large magnetoresistance when the transport direction and magnetic field direction coincide along the wall plane [10]. This suggests a possible magnetotransport mechanism roughly akin to that in the colossal magnetoresistive manganites, albeit in two dimensions, in which the magnetic moments in the domain wall plane behave like those in a spin glass; an applied magnetic field aligns the moments and thus reduces the resistance to transport.…”

“…For example, figure 1 shows the magnetotransport behaviour of 109 • domain walls, an atomic resolution image of which is shown in figure 1a. Conducting atomic force microscopy (AFM)-based measurements (figure 1b) show that the walls are less resistive (compared with the domain itself), typically by two to three orders of magnitude [10]. Temperature-dependent measurements show that the transport is still semiconducting in nature, albeit with a smaller activation energy.…”