Co nanoclusters as origin of ferromagnetism in sol‐gel synthesized Zn<sub>1‐x</sub>Co<sub>x</sub>O (x = 0.05, 0.10 and 0.15) samples

Sharma, Vijay Kumar; Varma, G. D.

doi:10.1002/crat.200811179

Cited by 9 publications

(4 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…During the course of our extended study of dilute magnetism in Fe-doped BaTiO 3 single crystal, it turned out to be extremely difficult to search for any small amounts of precipitated magnetic phases using conventional tools [28][29][30][31][32][33], because they are expected to be buried deep within the enormous volume of the 'nonmagnetic' bulk matrix. In fact, in the present case, simple lab-based techniques failed to indicate Fe-metal precipitation even though significant changes in overall crystal and chemical compositions were revealed.…”

Section: Introductionmentioning

confidence: 99%

Investigating the development of spurious magnetism in single crystalline BaTi_0.95Fe_0.05O_3−δwith highδby local structural probes

Chakraborty

Meneghini

Aquilanti

et al. 2014

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

BaTi₀.₉₅Fe₀.₀₅O₃-δ has been suggested to be an intrinsic dilute magnetic oxide with a clear dependence of magnetism on oxygen vacancy concentration. However, it has also been shown that the dopant Fe ions distribute themselves rather inhomogeneously within the lattice, though without disrupting the crystal phase of the parent BaTiO₃. With the help of x-ray absorption spectroscopy (XAS), here we find that the incorporation of a larger amount of anion vacancy pushes this inhomogeneity to the extreme, leading to the precipitation of Fe metal clusters. It is also observed that the residual solid, without the Fe-metal cluster, undergoes massive structural and compositional reorganization.

show abstract

Section: Introductionmentioning

confidence: 99%

Investigating the development of spurious magnetism in single crystalline BaTi_0.95Fe_0.05O_3−δwith highδby local structural probes

Chakraborty

Meneghini

Aquilanti

et al. 2014

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

show abstract

“…With increasing concen-tration of cobalt doping in the samples, the spectra remain the same with decrease in XRD intensity, indicating that Co ions successfully substituting the Zn sites in the wurtzite structure. Only for the sample with x = 0.15, there are some small peaks corresponding to Co3O4 [21]. The almost same crystallite size, stable wurtzite structure and absence of impurity phases with increasing concentration of Co 2+ doping for all samples could be attributed to the similarity of size of Zn 2+ and Co 2+ ions (ionic radius of Co 2+ is 0.59Å, Zn 2+ is 0.60Å) [20] .…”

Section: Experimental Methodsmentioning

confidence: 88%

Magnetic Properties of Zn1-xCoxO Nanoparticles.

Singh

Bandyopadhyay³

2014

Physics Procedia

View full text Add to dashboard Cite

Zn1-xCoxO nanoparticles have been synthesized at various concentrations of Co 2+ doping (0.005 x 0.15) by wet chemical method. Particle size was ranging from 34 -45 nm. The magnetic moment increases from x = 0.005 and 0.01 sample to x = 0.04 sample drastically showing a value of magnetic moment as high as 8.54 B/Cations and then decreases for x = 0.09 and 0.15 values of Co 2+ doping. There is almost paramagnetic behaviour for x = 0.005 and 0.01 Co 2+ doped samples. The x = 0.04 sample shows ferromagnetic ordering. Ferromagnetic behaviour decreases for x = 0.09 and 0.15 samples as the antiferromagnetic interaction dominates at higher Co 2+ doping concentrations. To probe the source of magnetism, we have undertaken photoluminescence studies also which revealed the presence of oxygen and Zinc vacancies along with other defects.

show abstract

“…One of the major thrusts in ongoing research is the formation of phase pure DMS materials and achievement of ferromagnetism with reasonable magnetization [3,4]. Theoretical investigations suggest that semiconductors with wide band-gaps are the most potential candidates for this purpose [5,6]. ZnO has a direct band-gap ( = 3.37 eV) among semiconductors with hexagonal (wurtzite) crystal structure.…”

Section: Introductionmentioning

confidence: 99%

Phase Pure Synthesis and Morphology Dependent Magnetization in Mn Doped ZnO Nanostructures

Saleem¹,

Atiq

Ramay

et al. 2014

Advances in Materials Science and Engineering

View full text Add to dashboard Cite

Zn0.95Mn0.05O nanostructures were synthesized using sol gel derived autocombustion technique. As-burnt samples were thermally annealed at different temperatures (400, 600, and 800°C) for 8 hours to investigate their effect on structural morphology and magnetic behavior. X-ray diffraction and scanning electron microscopic studies demonstrated the improvement in crystallinity of phase pure wurtzite structure of Mn doped ZnO with variation of annealing temperature. Energy dispersive X-ray elemental compositional analysis confirmed the exact nominal compositions of the reactants. Electrical resistivity measurements were performed with variation in temperature, which depicted the semiconducting nature similar to parent ZnO after 5 at% Mn doping. Magnetic measurements by superconducting quantum interference device detected an enhanced trend of ferromagnetic interactions in thermally annealed compositions attributed to the improved structural morphology and crystalline refinement process.

show abstract

Co nanoclusters as origin of ferromagnetism in sol‐gel synthesized Zn_1‐xCo_xO (x = 0.05, 0.10 and 0.15) samples

Cited by 9 publications

References 31 publications

Investigating the development of spurious magnetism in single crystalline BaTi_0.95Fe_0.05O_3−δwith highδby local structural probes

Investigating the development of spurious magnetism in single crystalline BaTi_0.95Fe_0.05O_3−δwith highδby local structural probes

Magnetic Properties of Zn1-xCoxO Nanoparticles.

Phase Pure Synthesis and Morphology Dependent Magnetization in Mn Doped ZnO Nanostructures

Contact Info

Product

Resources

About

Co nanoclusters as origin of ferromagnetism in sol‐gel synthesized Zn1‐xCoxO (x = 0.05, 0.10 and 0.15) samples

Cited by 9 publications

References 31 publications

Investigating the development of spurious magnetism in single crystalline BaTi0.95Fe0.05O3−δwith highδby local structural probes

Investigating the development of spurious magnetism in single crystalline BaTi0.95Fe0.05O3−δwith highδby local structural probes

Magnetic Properties of Zn1-xCoxO Nanoparticles.

Phase Pure Synthesis and Morphology Dependent Magnetization in Mn Doped ZnO Nanostructures

Contact Info

Product

Resources

About

Co nanoclusters as origin of ferromagnetism in sol‐gel synthesized Zn_1‐xCo_xO (x = 0.05, 0.10 and 0.15) samples

Investigating the development of spurious magnetism in single crystalline BaTi_0.95Fe_0.05O_3−δwith highδby local structural probes

Investigating the development of spurious magnetism in single crystalline BaTi_0.95Fe_0.05O_3−δwith highδby local structural probes