Accounting oxygen vacancy for half-metallicity and magnetism in Fe-doped CeO2 dilute magnetic oxide

Saini, Hardev S.; Singh, Mukhtiyar; Reshak, A.H.; Kashyap, Manish K.

doi:10.1016/j.commatsci.2013.02.029

Cited by 46 publications

(16 citation statements)

References 39 publications

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“…18 Such study to develop new material with room temperature ferromagnetism along with the semiconducting properties is very useful to engineer and design new spintronics devices like magnetic sensors, spin light emitting diodes, spin valves and ultra-fast optical switches. 19 CeO 2 is a chemically stable oxide with capacity to store or release oxygen due to the variation of the oxidation state from Ce 4+ to Ce 3+ . The variation of the oxidation state, CeO 2 can form stable oxygen vacancies in the matrix.…”

Section: +mentioning

confidence: 99%

Controlled synthesis and magnetic properties of monodispersed ceria nanoparticles

et al. 2015

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In the present study, monodispersed CeO2 nanoparticles (NPs) of size 8.5 ± 1.0, 11.4 ± 1.0 and 15.4 ± 1.0 nm were synthesized using the sol-gel method. Size-dependent structural, optical and magnetic properties of as-prepared samples were investigated by X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), high resolution transmission electron microscopy (HR-TEM), ultra-violet visible (UV-VIS) spectroscopy, Raman spectroscopy and vibrating sample magnetometer (VSM) measurements. The value of optical band gap is calculated for each particle size. The decrease in the value of optical band gap with increase of particle size may be attributed to the quantum confinement, which causes to produce localized states created by the oxygen vacancies due to the conversion of Ce4+ into Ce3+ at higher calcination temperature. The Raman spectra showed a peak at ∼461 cm-1 for the particle size 8.5 nm, which is attributed to the 1LO phonon mode. The shift in the Raman peak could be due to lattice strain developed due to variation in particle size. Weak ferromagnetism at room temperature is observed for each particle size. The values of saturation magnetization (Ms), coercivity (Hc) and retentivity (Mr) are increased with increase of particle size. The increase of Ms and Mr for larger particle size may be explained by increase of density of oxygen vacancies at higher calcination temperature. The latter causes high concentrations of Ce3+ ions activate more coupling between the individual magnetic moments of the Ce ions, leading to an increase of Ms value with the particle size. Moreover, the oxygen vacancies may also produce magnetic moment by polarizing spins of f electrons of cerium (Ce) ions located around oxygen vacancies, which causes ferromagnetism in pure CeO2 samples.

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Section: +mentioning

confidence: 99%

Controlled synthesis and magnetic properties of monodispersed ceria nanoparticles

et al. 2015

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“…Since the remarkable discovery of HM ferromagnetism in NiMnSb by de Groot et al [5], the research in this field has made a significant development. Today, despite the theoretical prediction of half-metallicity in Heusler alloys [6][7][8][9][10][11][12][13] and in other systems [14][15][16], this character has been very well confirmed experimentally also [17][18][19].…”

Section: Introductionmentioning

confidence: 81%

Disorder dependent half-metallicity in Mn2CoSi inverse Heusler alloy

Singh

Saini²,

Thakur

et al. 2013

Journal of Solid State Chemistry

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“…During the past decades, the half-metallic materials have attracted so much attention due to their great potential in the field of spintronics device application [1][2][3][4][5][6][7][8][9][10], such as tunnelling magnetoresistance (TMR) devices [11], magnetic tunnel junctions [12,13] and spin injection devices [14]. The concept of half-metallic property was initially proposed by De Groot et al basing on NiMnSb half-Heusler alloy calculations [15], which behaved as the metal for one spin direction and as the semiconductor or isolator for the opposite spin direction.…”

Section: Introductionmentioning

confidence: 99%