Structural and Magnetic Properties of Nickel Oxide Nanopowders

2010 ◽  
Vol 168-169 ◽  
pp. 341-344 ◽  
Author(s):  
Nina Mironova-Ulmane ◽  
A. Kuzmin ◽  
J. Grabis ◽  
I. Sildos ◽  
V.I. Voronin ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Magnetic Properties ◽  
Neutron Diffraction ◽  
Nickel Oxide ◽  
Room Temperature ◽  
Squid Magnetometry ◽  
X Ray ◽  
Micro Raman Spectroscopy ◽  
Antiferromagnetic Ordering ◽  
Structural And Magnetic Properties

Structure and magnetic properties of nickel oxide (NiO) nanopowders have been studied by X-ray/neutron diffraction, SQUID magnetometer, and micro-Raman spectroscopy. Our diffraction data indicate that at room temperature all NiO powders are antiferromagnetically ordered and have a rhombohedral (R-3m) phase. The SQUID magnetometry and Raman spectroscopy measurements support the presence of the antiferromagnetic ordering.

Structural and Magnetic Properties of La0.7Sr0.3Mn1-xNixO3 (x=0.05, 0.1, 0.2, 0.3, 0.4)

2011 ◽  
Vol 1327 ◽  
Author(s):  
Thomas F. Creel ◽  
Jinbo B. Yang ◽  
Mehmet Kahveci ◽  
Jagat Lamsal ◽  
Satish K. Malik ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Neutron Diffraction ◽  
Diffraction Data ◽  
Magnetic Measurements ◽  
Magnetic Ordering ◽  
Neutron Diffraction Data ◽  
Space Group ◽  
X Ray ◽  
Antiferromagnetic Ordering ◽  
Structural And Magnetic Properties

ABSTRACTWe have studied the structural and magnetic properties of La0.7Sr0.3Mn1-xNixO3 (x=0.05, 0.10, 0.20, 0.30, and 0.40) perovskites using x-ray and neutron diffraction and magnetic measurements. To our knowledge, there exists no neutron diffraction data available for this group of perovskite compositions. Neutron (λ = 1.479Å) and x-ray (λ = 1.5481Å; Cu Kα) powder diffraction indicate that for x ≥ 0.1 all samples are two-phase with a rhombohedral perovskite structure (space group R-3c) and a small amount of NiO (space group Fm3m). Neutron diffraction data for the perovskite phase at 12K and 300K show ferromagnetic ordering for x ≤ 0.2 and antiferromagnetic ordering for x = 0.4. However, for x = 0.3, neutron diffraction data at 12K show coexisting ferromagnetic and antiferromagnetic ordering while at 300K no magnetic ordering is found. Magnetic measurements indicate that the Curie temperature decreases with increasing Ni content. The NiO phase for all samples was found to have antiferromagnetic ordering at 12K and 300K. The magnetic measurements are consistent with the neutron diffraction data and together indicate long-range magnetic ordering for samples at low temperature and transitions from ferromagnetic to paramagnetic to antiferromagnetic ordering for samples at room temperature.

scholarly journals Thermal Annealing and Phase Transformation of Serpentine-Like Garnierite

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 188
Author(s):  
Arun Kumar ◽  
Michele Cassetta ◽  
Marco Giarola ◽  
Marco Zanatta ◽  
Monique Le Guen ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Raman Spectroscopy ◽  
Phase Transformation ◽  
Differential Thermal Analysis ◽  
Thermal Treatment ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
Thermally Induced ◽  
X Ray ◽  
Micro Raman Spectroscopy

This study is focused on the vibrational and microstructural aspects of the thermally induced transformation of serpentine-like garnierite into quartz, forsterite, and enstatite occurring at about 620 °C. Powder specimens of garnierite were annealed in static air between room temperature and 1000 °C. The kinetic of the transformation was investigated by means of thermogravimetric and differential thermal analysis, and the final product was extensively characterized via micro-Raman spectroscopy and X-ray diffraction. Our study shows that serpentine-like garnierite consists of a mixture of different mineral species. Furthermore, these garnierites and their composition can provide details based on the mineralogy and the crystalline phases resulting from the thermal treatment.

scholarly journals Structure and Magnetic Properties of Amorphous Fe-Zr-Nb-Cu-B-(Y) Ribons

2019 ◽  
Vol 70 (1) ◽  
pp. 233-235
Author(s):  
Joanna Gondro
Keyword(s):  
Magnetic Properties ◽  
Low Temperatures ◽  
Amorphous Alloys ◽  
Room Temperature ◽  
Time Stability ◽  
X Ray Diffraction ◽  
Soft Magnetic ◽  
X Ray ◽  
Amorphous Ribbons ◽  
Structural And Magnetic Properties

In this paper the results of the structural and magnetic properties for amorphous alloys ribbons Fe86Zr7Nb1Cu1B5 and Fe86Zr4Y3Nb1Cu1B5 were presented. From X-ray diffraction and M�ssbauer investigations we have stated that amorphous ribbons were fully amorphous. The investigated alloys, exhibit poor soft magnetic properties at room temperature. However, at low temperatures they show relatively large magnetic susceptibility and good its time stability.

THE GD CONCENTRATION DEPENDENCE OF THE MAGNETIC PROPERTIES OF ROOM TEMPERATURE FERROMAGNETIC ZNO:GD SEMICONDUCTOR

2009 ◽  
Vol 23 (17) ◽  
pp. 3550-3555 ◽  
Author(s):  
S. T. LIM ◽  
W. D. SONG ◽  
K. L. TEO ◽  
T. LIEW ◽  
T. C. CHONG
Keyword(s):  
Magnetic Properties ◽  
Room Temperature ◽  
Pulsed Laser ◽  
Solubility Limit ◽  
Laser Deposition ◽  
Implantation Technique ◽  
Zno Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structural And Magnetic Properties

We present structural and magnetic properties of ZnO films doped with rare-earth Gd ions at various concentrations, achieved by ion implantation technique and pulsed laser deposition (PLD) on ZnO (0001) single crystals and sapphire. X-ray diffraction shows Gd doping in ZnO and crystal quality degrades with increasing Gd concentration. Magnetization as a function of temperature revealed a positive magnetization at 305 K and a concave trend was observed for all samples for both implanted and PLD grown samples. The highest saturation magnetization was achieved for Gd concentration of x = 7.9 % (0.7 µ B / Gd ) and at dosage of 9.0 × 1015 cm -2 (2.6 µ B / Gd ) for the PLD grown and implanted samples, respectively. We believe that the Gd ion solubility limit in the implanted and PLD grown samples, of around 3% and 7.9%, respectively, are reached.

Effect of pH on the Structural and Magnetic Properties of Magnetite Nanoparticles Synthesised by Co-Precipitation

2011 ◽  
Vol 324 ◽  
pp. 129-132 ◽  
Author(s):  
Wegdan Ramadan ◽  
Marwa Kareem ◽  
Béatrice Hannoyer ◽  
Shanta Saha
Keyword(s):  
Particle Size ◽  
Raman Spectroscopy ◽  
Magnetic Properties ◽  
Magnetite Nanoparticles ◽  
Room Temperature ◽  
Ph Value ◽  
Magnetite Fe3o4 ◽  
Aqueous Method ◽  
Structural And Magnetic Properties ◽  
Co Precipitation

Magnetite, Fe3O4, nanoparticles were synthesized using co-precipitation aqueous method at room temperature and at different pH, from 8 to 12.5. The pH value was found to influence greatly the resulting phases and has no significant effect on the particle size. In all cases, magnetite was found to be the main phase but the contribution of Goethite phase was identified clearly with the increase in pH. Significant reduction in saturation magnetization was evident. Structural and magnetic properties of the nanoparticles were examined using; XRD, TEM, Raman Spectroscopy and SQUID.

Photoluminescence and Magnetic Properties of Undoped and (Mn, Co) co-doped ZnO Nanoparticles

2020 ◽  
Vol 16 (4) ◽  
pp. 655-666
Author(s):  
Mona Rekaby
Keyword(s):  
Magnetic Properties ◽  
Zno Nanoparticles ◽  
Room Temperature ◽  
Magnetic Measurements ◽  
Structural Defects ◽  
Ferromagnetic Behavior ◽  
Secondary Phases ◽  
Antiferromagnetic Ordering ◽  
Doped Zno ◽  
Co Doped

Objective: The influence of Manganese (Mn2+) and Cobalt (Co2+) ions doping on the optical and magnetic properties of ZnO nanoparticles was studied. Methods: Nanoparticle samples of type ZnO, Zn0.97Mn0.03O, Zn0.96Mn0.03Co0.01O, Zn0.95Mn0.03 Co0.02O, Zn0.93Mn0.03Co0.04O, and Zn0.91Mn0.03Co0.06O were synthesized using the wet chemical coprecipitation method. Results: X-ray powder diffraction (XRD) patterns revealed that the prepared samples exhibited a single phase of hexagonal wurtzite structure without any existence of secondary phases. Transmission electron microscope (TEM) images clarified that Co doping at high concentrations has the ability to alter the morphologies of the samples from spherical shaped nanoparticles (NPS) to nanorods (NRs) shaped particles. The different vibrational modes of the prepared samples were analyzed through Fourier transform infrared (FTIR) measurements. The optical characteristics and structural defects of the samples were studied through Photoluminescence (PL) spectroscopy. PL results clarified that Mn2+ and Co2+ doping quenched the recombination of electron-hole pairs and enhanced the number of point defects relative to the undoped ZnO sample. Magnetic measurements were carried out at room temperature using a vibrating sample magnetometer (VSM). (Mn, Co) co-doped ZnO samples exhibited a ferromagnetic behavior coupled with paramagnetic and weak diamagnetic contributions. Conclusion: Mn2+ and Co2+ doping enhanced the room temperature Ferromagnetic (RTFM) behavior of ZnO. In addition, the signature for antiferromagnetic ordering between the Co ions was revealed. Moreover, a strong correlation between the magnetic and optical behavior of the (Mn, Co) co-doped ZnO was analyzed.

Effect of Annealing temperature on the Structural and Magnetic Properties of TbxY3-xFe5O12(x = 0.0, 1.0, 2.0) Thin Films Prepared by Sol-Gel Process

2012 ◽  
Vol 501 ◽  
pp. 236-241 ◽  
Author(s):  
Ftema W. Aldbea ◽  
Noor Bahyah Ibrahim ◽  
Mustafa Hj. Abdullah ◽  
Ramadan E. Shaiboub
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Vibrating Sample Magnetometer ◽  
X Ray ◽  
Garnet Phase ◽  
Sol Gel Process ◽  
Amorphous Structures

Thin films nanoparticles TbxY3-xFe5O12 (x=0.0, 1.0, 2.0) were prepared by the sol-gel process followed by annealing process at various annealing temperatures of 700° C, 800° C and 900° C in air for 2 h. The results obtained from X-ray diffractometer (XRD) show that the films annealed below 900°C exhibit peaks of garnet mixed with small amounts of YFeO3 and Fe2O3. Pure garnet phase has been detected in the films annealed at 900°C. Before annealing the films show amorphous structures. The particles sizes measurement using the field emission scanning electron microscope (FE-SEM) showed that the particles sizes increased as the annealing temperature increased. The magnetic properties were measured at room temperature using the vibrating sample magnetometer (VSM). The saturation magnetization (Ms) of the films also increased with the annealing temperature. However, different behavior of coercivity (Hc) has been observed as the annealing temperature was increased.

scholarly journals Use of WetSEM® capsules for convenient multimodal scanning electron microscopy, energy dispersive X-ray analysis, and micro Raman spectroscopy characterisation of technetium oxides

2021 ◽  
Author(s):  
D. J. Bailey ◽  
M. C. Stennett ◽  
J. Heo ◽  
N. C. Hyatt
Keyword(s):  
Raman Spectroscopy ◽  
Low Cost ◽  
Powder Materials ◽  
Spectroscopy Analysis ◽  
X Ray ◽  
Micro Raman Spectroscopy ◽  
Hazard And Risk ◽  
Sem Imaging ◽  
General User ◽  
532 Nm

AbstractSEM–EDX and Raman spectroscopy analysis of radioactive compounds is often restricted to dedicated instrumentation, within radiological working areas, to manage the hazard and risk of contamination. Here, we demonstrate application of WetSEM® capsules for containment of technetium powder materials, enabling routine multimodal characterisation with general user instrumentation, outside of a controlled radiological working area. The electron transparent membrane of WetSEM® capsules enables SEM imaging of submicron non-conducting technetium powders and acquisition of Tc Lα X-ray emission, using a low cost desktop SEM–EDX system, as well as acquisition of good quality μ-Raman spectra using a 532 nm laser.

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