scholarly journals Preparation, Electronic Properties, and Powder-XRD Structure Analysis of 3,5-Bis(pyridin-2-yl)-H-1,2,4-triazoledichloridocopper(II)

2020 ◽  
Vol 20 (6) ◽  
pp. 1422
Author(s):  
Kristian Handoyo Sugiyarto ◽  
Isti Yunita ◽  
Harold Andrew Goodwin
Keyword(s):  
Magnetic Properties ◽  
Low Temperatures ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Powder Xrd ◽  
Magnetic Interactions ◽  
Ligand Field ◽  
R Factor ◽  
Bright Green ◽  
Lower Temperature

Salt of [Cu(bptrzH)Cl2], (bptrzH = 3,5-bis(pyridin-2-yl)-H-1,2,4-triazole) has been prepared and characterized its electronic spectral and magnetic properties. This salt is paramagnetic with magnetic moment, μs, being 1.77–1.78 BM at 293 K, but decreased significantly with decreasing temperature to be 0.60–0.63 BM at 90 K, indicating antiferromagnetic nature. This is associated with Cu–Cu magnetic interactions at low temperatures, and suggests that the salt adopt an octahedrally polymeric structure. The electronic spectrum of this salt reveals a strong ligand field band centered at about 13,000 cm–1 and a very strong charge transfer absorption at about 23,000–24,000 cm–1. The spectrum is better resolved at lower temperature and this is parallel to the slight change in color from yellowish-green at room temperature to bright green at low temperature (90 K). The powder XRD of this complex was refined by Le Bail method of Rietica program and found to be fit as triclinic symmetry of space group PĪ with the figure of merit: Rp = 5.02; Rwp = 7.95; Rexp = 5.40; Bragg R-Factor = 0.05; and GOF = 2.166.

Nano-structured (Mo,Ti)C-C-Ni magnetic powder

2018 ◽  
Vol 1 (86) ◽  
pp. 5-13
Author(s):  
S.M. Kaczmarek ◽  
A. Biedunkiewicz ◽  
T. Bodziony ◽  
P. Figiel ◽  
T. Skibiński ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Anisotropy ◽  
Long Range ◽  
Low Temperatures ◽  
Temperature Increase ◽  
Magnetic Interactions ◽  
Magnetic Powder ◽  
Magnetic Phases

Different kinds of structural and magnetic phases have been found in the investigated compounds, e.g. (Mo, Ti)C, C, Ni. It was found that such different phases create different kinds of magnetic interactions, from paramagnetic, antiferromagnetic up to superparamagnetic. Significant magnetic anisotropy has been revealed for low temperatures, which lowers with temperature increase. Moreover, non-usual increasing of the magnetization as a function of temperature was observed. It suggests, that overall long-range AFM interaction may be responsible for the magnetic properties.

scholarly journals Fabrication and magnetic properties of hierarchical nickel microwires with nanothorns

2010 ◽  
Vol 8 (2) ◽  
pp. 434-439 ◽  
Author(s):  
Junhao Zhang ◽  
Ling Yang ◽  
Xiaofang Cheng ◽  
Jinmeng Zhang ◽  
Fucai Li
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Magnetic Properties ◽  
Room Temperature ◽  
Cooperative Effect ◽  
Magnetic Interactions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

AbstractHierarchical nickel microwires with nanothorns were fabricated through a reduction of nickelous salt with hydrazine in diethanolamine. The product was characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDS). The growth mechanism of the nickel microwires with nanothorns is proposed, based on the evolution of the structures and morphologies, which could be ascribed to the cooperative effect of the complexant of diethanolamine and inherent magnetic interactions. Magnetic properties of the product were measured at room temperature and compared with other shaped counterparts.

Enhancement of Thermopower due to Deficiency of Sb in FeSb2

2013 ◽  
Vol 665 ◽  
pp. 179-181 ◽  
Author(s):  
Anup V. Sanchela ◽  
Varun Kushwaha ◽  
Ajay. D. Thakur ◽  
C.V. Tomy
Keyword(s):  
Thermal Conductivity ◽  
Seebeck Coefficient ◽  
Low Temperatures ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Parent Compound ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
Thermoelectric Power Factor ◽  
Anomalous Peak

FeSb2 was recently found to be a narrow-gap semiconductor with strong electronelectron correlation and a large thermopower at low temperatures. We report measurements of the electrical resistivity, Seebeck coefficient and thermal conductivity between 5 K to 300 K on polycrystalline samples of FeSb2 and FeSb1.9. We found that the deficiency of Sb in the parent compound leads to a giant anomalous peak in thermopower (S) at low temperatures, reaching ~ 426 μV/K at 20 K, resulting in a high thermoelectric power factor at low temperatures, achieving 10 μW/K2m at 27 K.. Consequently, a significantly enhanced thermoelectric figure of merit ZT ~ 0.0015 is achieved near room temperature. At low temperatures there is no improvement in ZT values due to the high thermal conductivity (phonon dominant region). Keywords: Seebeck coefficient, thermal conductivity, resistivity, thermoelectric figure of merit. PACS: 72.20.Pa, 71.27.+a, 71.28.+d

scholarly journals Structural, Chemical and Low Temperature Magnetic Properties of Lead Free 0.6NiFe2O4 - 0.4Na0.5Bi0.5TiO3 Magnetoelectric Composite

2021 ◽  
Author(s):  
G Jegadish Kumar ◽  
M Sarathbavan ◽  
E Senthil Kumar ◽  
M Navaneethan ◽  
K Kamala Bharathi
Keyword(s):  
Magnetic Properties ◽  
Low Temperature ◽  
Saturation Magnetization ◽  
Room Temperature ◽  
Magnetization Measurement ◽  
Magnetic Interactions ◽  
Lead Free ◽  
Zero Field ◽  
Temperature Dependent ◽  
Magnetoelectric Composite

Abstract We report on structural, chemical and low temperature magnetic properties of lead free 0.6NiFe2O4 - 0.4Na0.5Bi0.5TiO3 composite. NiFe2O4 (NFO) and Na0.5Bi0.5TiO3 (NBTO) are seen to crystallize in inverse spinel and perovskite structure respectively. 0.6NiFe2O4 - 0.4Na0.5Bi0.5TiO3 composite exhibits both NFO and NBTO phases in appropriate composition. Zero field cooled (ZFC) and field cooled (FC) magnetization measurements carried out from 15 K to 300 K shows a large bifurcation at room temperature. ZFC and FC magnetization measurement exhibit a hump at Tm ⁓ 259.5 K, indicates the possible existence of competing magnetic interactions in 0.6NiFe2O4 - 0.4Na0.5Bi0.5TiO3 composite. Saturation magnetization, remanent magnetization and coercivity values are observed to increase with decreasing the temperature. Temperature dependent saturation magnetization is fit to the Bloch’s law. Magnetocrystalline anisotropy (K1) value at various temperatures are estimated and is seen to increase from 0.23 x104 erg/cc (at 300 K) to 0.34 x104 erg/cc (at 15 K).

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.

scholarly journals PHOTODYNAMIC HEMOLYSIS AT LOW TEMPERATURES

1954 ◽  
Vol 37 (3) ◽  
pp. 301-311 ◽  
Author(s):  
Harold F. Blum ◽  
Elizabeth Flagler Kauzmann
Keyword(s):  
Solid State ◽  
Low Temperatures ◽  
Room Temperature ◽  
Photosensitized Oxidation ◽  
Higher Temperature ◽  
Semi Solid ◽  
Lower Temperature ◽  
Dye Molecule

It is shown that photodynamic hemolysis may occur at –79°C. if the erythrocytes are suspended in a solution containing 70 per cent glycerol which prevents hemolysis by freezing; but that there is no hemolysis under the same conditions at –210°C. At the higher temperature the viscosity of the solution is still low enough to permit appreciable movement of molecules, whereas at the lower temperature the molecules must be virtually immobile. The findings are compatible with the idea that the dye molecule acts in a cycle, bringing about successive oxidations by O2 molecules, as has been shown for photodynamic hemolysis at room temperature. The assumption of a combination between dye, O2, and substrate does not explain photosensitized hemolysis in the semi-solid state. The mechanism of photosensitized oxidation by O2 is discussed.

Influence of Co Moment on Magnetic Properties of Co2Sm2W3O14 Tungstate

2011 ◽  
Vol 170 ◽  
pp. 1-4 ◽  
Author(s):  
P. Urbanowicz ◽  
Elzbieta Tomaszewicz ◽  
Tadeusz Groń ◽  
Henryk Duda ◽  
Andrzej W. Pacyna ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Magnetic Moment ◽  
Low Temperatures ◽  
Magnetic Measurements ◽  
Spontaneous Magnetization ◽  
Magnetic Interactions ◽  
Orbital Contribution ◽  
Weiss Temperature ◽  
Orthorhombic System

The Co2Sm2W3O14 compound crystallizes in the orthorhombic system, and melts congruently at 1443 K. The magnetic measurements showed that Co2Sm2W3O14 is a paramagnet in the temperature range 4.2-225 K showing both the residual magnetic interactions since the paramagnetic Curie-Weiss temperature   0 and the uncompensated temperature independent contributions of magnetic susceptibility since 0  0. The Brillouin fit of the Landé factor revealed an increase of the orbital contribution to the total magnetic moment of the compound what seems to be responsible for its hard and spontaneous magnetization at low temperatures.

STRUCTURAL CHARACTERIZATION, PREPARATION AND MAGNETIC PROPERTIES OF SEVERAL ROOM-TEMPERATURE MAGNETIC OXIDES WITH THE PEROVSKITE-LIKE STRUCTURE

1977 ◽  
Vol 38 (C1) ◽  
pp. C1-95-C1-101 ◽  
Author(s):  
B. BOCHU ◽  
M. N. DESCHIZEAUX ◽  
J. C. JOUBERT ◽  
J. CHENAVAS ◽  
A. COLLOMB ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Structural Characterization ◽  
Room Temperature ◽  
Magnetic Oxides

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.

Sign in / Sign up

Export Citation Format

Share Document