Room temperature ferromagnetism in chemically synthesized ZnO rods

Kumar, Shalendra; Kim, Y.J.; Koo, Bon Heun; Gautam, Sanjeev; Chae, Keun Hwa; Kumar, Ravi; Lee, C.G.

doi:10.1016/j.matlet.2008.09.057

Cited by 62 publications

(21 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…[3][4][5] Till date many potential compounds such as: pure and transition metal (TM) doped ZnO, TiO 2 , CeO 2 and HfO 2 etc., have been observed to show RTFM but the intrinsic origination of the FM is still under contest. [6][7][8][9][10][11] Even thought the FM reported in the same system by different groups * Authors to whom correspondence should be addressed. varies widely, ranging from RTFM to no magnetic ordering.…”

Section: Introductionmentioning

confidence: 99%

Structural and Magnetic Properties of Ni Doped CeO<SUB>2</SUB> Nanoparticles

Kumar¹,

Kim²,

Koo³

et al. 2010

J. Nanosci. Nanotech.

Self Cite

View full text Add to dashboard Cite

We report room temperature ferromagnetism in Ni doped CeO2 nanoparticles using X-ray diffraction (XRD), high resolution transmission electron microscopy (HR-TEM), and dc magnetization measurements. Nanoparticles of Ce(1-x)Ni(x)O2 (0.0 < or = x < or = 0.10) were prepared by using a co-precipitation method. XRD measurements indicate that all samples exhibit single phase nature with cubic structure and ruled out the presence of any secondary phase. Lattice parameters, strain and particle size calculated from XRD data have been found to decrease with increase in Ni doping. Inter-planner distance measured from HR-TEM images for different Ni doped samples indicate that Ni ions are substituting Ce ions in CeO2 matrix. Magnetization measurements performed at room temperature display weak ferromagnetic behavior of Ce(1-x)Ni(x)O2 (0.0 < or = x < or = 0.10) nanoparticles. Magnetic moment calculated from magnetic hysteresis loop was found to increases with Ni doping up to 7% and then start decreasing with further doping.

show abstract

Section: Introductionmentioning

confidence: 99%

Structural and Magnetic Properties of Ni Doped CeO<SUB>2</SUB> Nanoparticles

Kumar¹,

Kim²,

Koo³

et al. 2010

J. Nanosci. Nanotech.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Although earlier reports have shown ferromagnetic ordering in ZnO nanoparticles, thin films, and nanorods [2][3][4]8], to the best of our knowledge, no study has been reported on the informative particle size/film thickness dependence of the evolution of magnetism in ZnO. In this present study we report on the magnetic properties at RT for pure ZnO thin films deposited by DC Magnetron sputtering from a pure Zn metal target.…”

Section: Introductionmentioning

confidence: 70%

“…Saturation magnetization values spreading over a wide range, 10 -4 -10 -1 emu/g, have been reported for pristine undoped ZnO, HfO 2 , TiO 2 and SnO 2 [1][2][3][4][5][6][7][8]. Saturation magnetization values spreading over a wide range, 10 -4 -10 -1 emu/g, have been reported for pristine undoped ZnO, HfO 2 , TiO 2 and SnO 2 [1][2][3][4][5][6][7][8].…”

Section: Introductionmentioning

confidence: 87%

On the defect induced ferromagnetic ordering above room-temperature in undoped and Mn doped ZnO thin films

Kapilashrami

Ström

et al. 2009

MRS Proc.

View full text Add to dashboard Cite

Evidence for long range ferromagnetic order above room-temperature, RTFM, in pristine ZnO, In 2 O 3 , TiO 2 nanoparticles and thin films, containing no nominal magnetic elements have been reported recently. This could question the origin of RTFM in doped dilute alloys if for example the ZnO matrix itself develops a defect induced magnetic order with a significant moment per unit cell. In this presentation we report a systematic study of the film thickness dependence of RTFM in pure ZnO deposited by DC Magnetron Sputtering. We observe a maximum in the saturation magnetization, M S , value of 0.62 emu/g (0,018 µ B /unit cell), for a ~480 nm film deposited in an oxygen ambience of appropriate pressure. Above a thickness of around 1 µm the films are diamagnetic as expected. We thus see a sequential transition from ferromagnetism to para-and eventual diamagnetism as a function of film thickness in ZnO. We also find that in such a ZnO matrix with a maximum intrinsic defect induced moment, on doping with Mn the maximum enhanced M S value of 0.78 emu/g is obtained for 1at.% Mn doping. With this approach of appropriate doping in a defect tailored matrix, we routinely obtain RTFM in both undoped and Mn-doped ZnO thin films.

show abstract

“…It is observed that ZnO nano particles exhibit a ferromagnetic behavior with coercivity (H C ) of 286 Oe, saturation magnetization (M S ) of 0.973 emu/g and remnant magnetization (M R ) = 0.199 emu/g. Some groups have also reported ferromagnetism in pure ZnO nano particles and thin films [20][21][22][23][24][25][26]. They intend that ferromagnetism is the universal feature of the nano particles of non-magnetic oxides.…”

Section: Xrd Analysismentioning

confidence: 99%

“…Zubiaga et al [28] study defect in ZnO bulk using positron annihilation life time spectroscopy and reported the presence of Zn vacancies in pure ZnO. Therefore, the RTFM in pure ZnO rods are due to the Zn vacancies induced spin polarization [26]. [29][30][31] indicate occurrence of ferromagnetic ordering in nanocrystals of nonmagnetic solids and ions [29] (Zn 2+ and O 2− ) due to surface defects.…”

Section: Xrd Analysismentioning

confidence: 99%

Effect of Annealing on the Structural and Magnetic Properties of 3% Sm Doped ZnO

Hantour¹,

El-Mohsen²,

El-Sayed³

et al. 2018

IJECEC

View full text Add to dashboard Cite

The present study focuses on the structural and magnetic properties of Sm doped ZnO at 3% concentrations.These compounds have been synthesized by a chemical coprecipitation method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and magnetization method (M-H). The XRD pattern of all the samples showed ZnO hexagonal wurtzite structure with sharp and intense peaks with small change in lattice parameters due to Sm doping in ZnO, indicating the substitution of Sm ion for Zn sites. Magnetic measurements show an enhancement in room temperature ferromagnetism (RTFM) with Sm doping. Ferromagnetic behavior exists over and above the diamagnetic behavior, RTFM related to The Zn vacancies and diamagnetic (which exists over alarge scale) related to the oxygen vacancies which mediate the interaction of dopant ions.

show abstract

Room temperature ferromagnetism in chemically synthesized ZnO rods

Cited by 62 publications

References 17 publications

Structural and Magnetic Properties of Ni Doped CeO<SUB>2</SUB> Nanoparticles

Structural and Magnetic Properties of Ni Doped CeO<SUB>2</SUB> Nanoparticles

On the defect induced ferromagnetic ordering above room-temperature in undoped and Mn doped ZnO thin films

Effect of Annealing on the Structural and Magnetic Properties of 3% Sm Doped ZnO

Contact Info

Product

Resources

About