Magnetic properties of Fe-doped NiO nanoparticles

Kurokawa, A.; Sakai, Naoki; Zhu, L.; Takeuchi, Hidenori; Yano, Shinya; Yanoh, T.; Onuma, Kazuki; Takaya, Kenichi; Miike, K.; Miyasaka, Toshiki; Ichiyanagi, Yuko

doi:10.3938/jkps.63.716

Cited by 8 publications

(4 citation statements)

References 15 publications

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“…Therefore, a question remains unanswered: what could be the possible mechanism for RT FM properties from TM-doped TMOs? To answer this question, we summarize the grain size ( d ) dependency of the reported RT magnetic properties from Ni 1– x M x O (M = Cr, Mn, ,,, Fe, ,,,− , Co, ,, Cu, Zn, , Sn, and Ce) and Ni 1– x Fe x O in Figures a and b, respectively, where the vertical axis represents the concentration x of the dopant. Here different colors are used to represent the grain-size-dependent magnetic properties of undoped NiO NPs as discussed in the Introduction, which can be split into three regions (Re), namely Re-I ( d ≤ 10 nm) SPM/SG/SSG, Re-II (10 nm ≤ d ≤ 30 nm) FM, and Re-III ( d ≥ 30 nm) AF (no finite size effect induced magnetism), respectively from left to right.…”

Section: Resultsmentioning

confidence: 99%

“…Interestingly, nonstoichiometric properties in NiO can be enhanced further by doping with TMs such as Cr, Mn, − Fe, ,− Co, ,, Cu, and Zn, , which mostly depend on the method of sample preparation, and experimental variables such as thermal treatment (i.e., grain size), oxygen activity, and the fraction of dopant . The above-mentioned factors affect the magnetic, structural, and electronic properties which are of great importance for the basic understanding of TMO-DMSs.…”

Section: Introductionmentioning

confidence: 99%

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Understanding the Magnetic Memory Effect in Fe-Doped NiO Nanoparticles for the Development of Spintronic Devices

Gandhi

Pradeep

Yeh

et al. 2018

ACS Appl. Nano Mater.

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Uniform hexagonal single phase Ni1–x Fe x O (x = 0, 0.01, 0.05, and 0.1) nanoparticles synthesized by a standard hydrothermal method are characterized with an enhanced lattice expansion along with a decrease in the microstrain, crystal size, and Ni occupancy as a function of the Fe concentration. The observed anomalous temperature and field dependent magnetic properties as a function of the Fe content were explained using a core–shell type structure of Ni1–x Fe x O nanoparticle such that the effect of Fe-doping has led to a decrease of disordered surface spins and an increase of uncompensated-core spins. Perfect incorporation of Fe3+ ions at the octahedral site of NiO was observed from the low Fe concentration; however, at a higher Fe content, 4:1 defect clusters (four octahedral Ni2+ vacancies surrounding an Fe3+ tetrahedral interstitial) are formed in the core of the nanoparticles, resulting in the transition of spin-glassy to the cluster-glassy system. An enhanced thermal magnetic memory effect is noted from the cluster-glassy system possibly because of increased intraparticle interactions. The outcome of this study is important for the future development of diluted magnetic semiconductor spintronic devices and the understanding of their fundamental physics.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Understanding the Magnetic Memory Effect in Fe-Doped NiO Nanoparticles for the Development of Spintronic Devices

Gandhi

Pradeep

Yeh

et al. 2018

ACS Appl. Nano Mater.

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“…According to recent findings, RT ferromagnetism in NiO NPs can be achieved through transition metal (TM)-doping, for example, Fe (either due to substitution or the formed defect clusters), which opens up their potential applications in the future advanced spintronic devices [ 13 , 14 , 15 ]. The properties of such a system can be tailored by controlling both the particle size and Fe-dopant concentration, which results in a complex magnetic property [ 16 , 17 , 18 , 19 , 20 , 21 , 22 ]. For instance, the doping of Fe 3+ ions in NiO either could replace the Ni ions or occupy an interstitial site.…”

Section: Introductionmentioning

confidence: 99%

Room Temperature Magnetic Memory Effect in Cluster-Glassy Fe-Doped NiO Nanoparticles

Gandhi

Kumar

et al. 2020

Nanomaterials

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The Fe-doped NiO nanoparticles that were synthesized using a co-precipitation method are characterized by enhanced room-temperature ferromagnetic property evident from magnetic measurements. Neutron powder diffraction experiments suggested an increment of the magnetic moment of 3d ions in the nanoparticles as a function of Fe-concentration. The temperature, time, and field-dependent magnetization measurements show that the effect of Fe-doping in NiO has enhanced the intraparticle interactions due to formed defect clusters. The intraparticle interactions are proposed to bring additional magnetic anisotropy energy barriers that affect the overall magnetic moment relaxation process and emerging as room temperature magnetic memory. The outcome of this study is attractive for the future development of the room temperature ferromagnetic oxide system to facilitate the integration of spintronic devices and understanding of their fundamental physics.

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“…In particular, the Coulomb force causes a higher energy state in the crystal when Mn 3+ ions occupy B sites in the spinel structure, and as a result, the site degeneracy is decreased and the tetragonal structure of the octahedron is distorted by the Jahn-Teller effect [1][2][3][4][5][6][7]. We have prepared several types of magnetic oxide nanoparticles including 3d transition metals encapsulated in amorphous SiO 2 using our novel preparation method and reported on their magnetic properties [8][9][10][11][12][13][14][15]. Recently, we have produced cubic spinel Cu ferrite nanoparticles without Jahn-Teller distortion, even though tetragonal Cu ferrite is normally stable with Jahn-Teller distortion [16].…”

Section: Introductionmentioning

confidence: 99%

Local Structure Control of Manganese Oxide Nanoparticles Encapsulated by Amorphous SiO<sub>2</sub>

Miyasaka

Takaya

Miike

et al. 2014

e-J. Surf. Sci. Nanotechnol.

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Spinel-structured manganese oxide (M Mn2O4: M = Fe, Ni, Co, Zn) nanoparticles encapsulated in amorphous SiO2 were produced using our original wet chemical method. From the X-ray diffraction patterns, the diameters were estimated to range from 4 nm to 23 nm, depending on the annealing temperature. Bulk manganese oxide crystals are known to have the spinel structure, and a tetragonal structure with Jahn-Teller distortion is a stable and normal phase. This Jahn-Teller distortion is induced by Mn 3+ ions at the octahedral B sites. However, we have successfully produced cubic structures consisting of FeMn2O4, CoMn2O4, and NiMn2O4 nanoparticles in which the local distortion is suppressed. In order to clarify the local structure, X-ray absorption fine structure (XAFS) and magnetization measurements were performed. The cubic and tetragonal structures were selectively obtained, and their magnetic properties were investigated.

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Magnetic properties of Fe-doped NiO nanoparticles

Cited by 8 publications

References 15 publications

Understanding the Magnetic Memory Effect in Fe-Doped NiO Nanoparticles for the Development of Spintronic Devices

Understanding the Magnetic Memory Effect in Fe-Doped NiO Nanoparticles for the Development of Spintronic Devices

Room Temperature Magnetic Memory Effect in Cluster-Glassy Fe-Doped NiO Nanoparticles

Local Structure Control of Manganese Oxide Nanoparticles Encapsulated by Amorphous SiO<sub>2</sub>

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