Giant magnetoresistance in Fe-In2O3 granular films

Observation of enhanced positive magnetoresistance at low temperatures in Ni0.8Fe0.2/C granular composites

“…In order to investigate this variation at different temperatures, the magnetoresistance isotherms were recorded for a typical composition (FN) 15 C 85 in both the geometries (i.e., LMR and TMR) and are shown in Fig. 4.…”

“…Such linear behavior is known to occur in an isotropic medium with a low volume fraction of insulating inclusions, but linearity holds good for only very high fields. Therefore, metal matrix systems, such as, Co-Cu, Ag-Fe and insulator matrix systems, such as, Fe-In 2 O 3 , Co-SiO 2 have been investigated by various groups [13][14][15][16]. In the metal matrix systems, the inter-particle magnetic interactions are mediated through the conduction electron, while in insulating matrix this possibility is considerably reduced which affects the magneto-transport behavior.…”

“…Therefore, transition-metal (TM) elements and rareearth (RE) metal elements are doped in semiconductor matrix to achieve higher MR values [17]. Interestingly enough TM-RE codoped polycrystalline In 2 O 3 shows giant positive MR values (85% at T = 2 K) at low temperatures but drops down to very small values as the temperature is raised [15]. Similar behavior was also observed in self-assembled Co@CoO nanoparticle arrays at temperature below 100 K [10], in non-magnetic silver chalcogenides [9], perovskite type manganites and inhomogeneous narrow gap semiconductors [11].…”

A first-principle prediction on the magnetism and electronic structure of Ti-doped CoO with two O vacancies

“…However, the observed ferromagnetism is weak and the Curie temperature is often below room temperature. Recently, the interesting magnetoresistance has been observed in the magnetic element added disordered oxide semiconductors with large dopant concentrations, such as FeeIn 2 O 3 [22], CoeZnO [23], NieCN [24], CoeTiO 2 [23,25], and FeeTieO [26].…”

Magnetism regulation of (In1−x Fe x )2O3 semiconductors prepared by sol-gel method

“…Lin Zhang [7] have found that Fe-In 2 O 3 granular films have the max giant magnetoresistance when T＝2 K. Jun He [6] et al reported that when the In 2 O 3 film with 15% Fe and 2% Cu co-doping, the saturation magnetization moment is next to 2 μ B /Fe. In T Ohno's study [8] , they decribed a ferromagnetic, highly transparent and conducting ITO-Fe-Cluster composite film.…”