Thermal instability of Co-substituted barium hexaferrites with U-type structure

2006 ◽  
Vol 21 (2) ◽  
pp. 420-427 ◽  
Author(s):  
Darja Lisjak ◽  
Paul McGuiness ◽  
Miha Drofenik
Keyword(s):  
Thermal Stability ◽  
Magnetic Properties ◽  
Solid State ◽  
Thermal Instability ◽  
High Energy ◽  
Type Structure ◽  
Stability Studies ◽  
X Ray ◽  
Barium Hexaferrites ◽  
Annealing Conditions

Thermal stability studies of Co-substituted barium hexaferrites with the U-type structure are reported. Samples were prepared using solid-state reaction and high-energy milling at 1300 and 1250 °C, respectively. The influence of different annealing conditions on their compositions and magnetic properties was studied. Thermal instability of the studied compounds was observed at as low as 600 °C. Through x-ray powder diffraction, chemical analysis, and thermomagnetic measurements it was confirmed that a degradation of the U-hexaferrites occurred during the annealing at 600–800 °C. The observed changes in the samples’ phase compositions and structures did not have a significant influence on their magnetization and microwave properties.

Color tunable Ca8ZnM(PO4)7 (M = Lu/Tb, Lu/Eu, Tb/Eu) phosphors: luminescence, energy transfer and thermal stability studies for n-UV white LEDs

2021 ◽  
Author(s):  
Jing Yan ◽  
Chunyan Jiang ◽  
Yulun Xian ◽  
Jianbang Zhou ◽  
Hong Li ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Energy Transfer ◽  
High Temperature ◽  
Solid State ◽  
Powder Diffraction ◽  
Stability Studies ◽  
X Ray ◽  
White Leds ◽  
Color Tunable ◽  
Xrd Patterns

A series of Tb3+- and Eu3+-doped Ca8ZnLu(PO4)7 (CZLP:Tb3+ and CZLP:Eu3+) as well as Ca8ZnTb(PO4)7:Eu3+ (CZTP:Eu3+) phosphors have been prepared via the traditional high-temperature solid-state reaction. X-ray powder diffraction (XRD) patterns...

Solid state synthesis of LiFePO4 studied by in situ high energy X-ray diffraction

2011 ◽  
Vol 21 (15) ◽  
pp. 5604 ◽  
Author(s):  
Zonghai Chen ◽  
Yang Ren ◽  
Yan Qin ◽  
Huiming Wu ◽  
Shengqian Ma ◽  
...  
Keyword(s):  
Solid State ◽  
High Energy ◽  
Solid State Synthesis ◽  
X Ray Diffraction ◽  
X Ray

Effect of Nitridation Magnetic Properties of Nanocrystalline Fe-Co Alloy Powders

2010 ◽  
Vol 654-656 ◽  
pp. 1106-1109
Author(s):  
Ya Qiong He ◽  
Chang Hui Mao ◽  
Jian Yang
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Alloy Powder ◽  
High Energy ◽  
X Ray Diffraction ◽  
Powder Mixtures ◽  
X Ray ◽  
Transmission Electron ◽  
Nitridation Temperature ◽  
Microstructure And Magnetic Properties

Nanocrystalline Fe-Co alloy powders, which were prepared by high-energy mechanical milling, were nitrided under the mixing gas of NH3/H2 in the temperature range from 380°C to 510°C. X-ray diffraction (XRD) was used to analyze the grain size and reaction during the processing. The magnetic properties of the nitrided powders were measured by Vibrating Sample Magnetometer (VSM). The results show that with the appearance of Fe4N phase after nitride treatment, and the grain-size of FeCo phase decreases with the increase of nitridation temperature between 380°C to 450°C.The saturation magnetization of nitrided alloy powder treated at 480°C is about 18% higher than that of the initial Fe-Co alloy powder, accompanied by the reduction of the coercivity. Transmission electron microscope (TEM) was used, attempting to further analyze the effect of Fe4N phase on microstructure and magnetic properties of the powder mixtures.

Facile low temperature solid state synthesis of iodoapatite by high-energy ball milling

RSC Advances ◽  
2014 ◽  
Vol 4 (73) ◽  
pp. 38718-38725 ◽  
Author(s):  
Fengyuan Lu ◽  
Tiankai Yao ◽  
Jinling Xu ◽  
Jingxian Wang ◽  
Spencer Scott ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Solid State ◽  
Low Temperature ◽  
Ball Milling ◽  
Thermal Annealing ◽  
Amorphous Matrix ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Solid State Synthesis ◽  
Energy Ball

High energy ball milled iodoapatite in the form of an amorphous matrix embedded with nanocrystals can be readily crystallized by subsequent low temperature thermal annealing, which greatly improves the thermal stability and iodine confinement.

Growth of lithium iron silicates nanoplates with high energy facets via polymorphs transition for ehanced lithium-ion extraction/insertion reaction

2021 ◽  
pp. 2151015
Author(s):  
Anran Duan ◽  
Huali Qiao ◽  
Miao He ◽  
Ting Wang ◽  
Dan Wang ◽  
...  
Keyword(s):  
High Temperature ◽  
Solid State ◽  
Thermal Instability ◽  
High Current Density ◽  
Lithium Ion ◽  
High Energy ◽  
Insertion Reaction ◽  
Ion Extraction ◽  
State Growth ◽  
Temperature Liquid

The anisotropic functionalities of nanostructured silicates are highly attractive for various applications, whereas the silicates’ nanostructure heavily relies on the reactions in low temperature liquid conditions. Due to the stubborn [SiO4][Formula: see text] lattice foundation and most surfactants’ thermal instability, it is extremely difficult to manipulate the nanostructure and preserve high energy lattice facets in the high temperature solid state growth of silicates. In this report, the polymorphs transition of Li2FeSiO4 is found to open a precious window for adsorbate–crystal interactions. By adsorbing on the intermediates of phase transition, Ethlyene glycol effectively promotes the solid-state growth of Li2FeSiO4 nanoplates at high temperature, of which the high energy (020) facet becomes the dominant and exhibits high activity for fast charge transportation. The obtained Li2FeSiO4 nanoplates show greatly enhanced reactivity for Li[Formula: see text] ions’ extraction/insertion, and exhibit excellent capacities at high current density (1–10 C) as the cathode material for lithium-ion batteries.

Zur Kenntnis quaternärer Telluride Cu2MM′Te4 mit Tetraederstrukturen / Quaternary Tellurides Cu2MM′Te4 with Tetrahedral Structures

1991 ◽  
Vol 46 (8) ◽  
pp. 1049-1052 ◽  
Author(s):  
H. Haeuseler ◽  
F. W. Ohrendorf ◽  
M. Himmrich
Keyword(s):  
Solid State ◽  
Type Structure ◽  
Solid State Reactions ◽  
X Ray

Quaternary tellurides Cu2MM′Te4 (M = Zn, Cd, Hg and M′ = Si, Ge, Sn) have been prepared by solid state reactions and characterized by X-ray powder methods. All 9 compounds crystallize in a stannite type structure.

Effect of (Ni, Zn)Ru mixtures on magnetic properties of barium hexaferrites yielded by high-energy milling

2005 ◽  
Vol 285 (3) ◽  
pp. 450-455 ◽  
Author(s):  
A. González-Angeles ◽  
G. Mendoza-Suárez ◽  
A. Grusková ◽  
J. Lipka ◽  
M. Papánová ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
High Energy ◽  
Barium Hexaferrites ◽  
High Energy Milling
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