scholarly journals Comparison of Precursor Preparation Routes on Final Density of Y3Fe5O12 Garnets Prepared via Reactive Sintering

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7316
Author(s):  
Kamil Wojciechowski ◽  
Radosław Lach ◽  
Magdalena Stan ◽  
Łukasz Łańcucki ◽  
Marta Gajewska ◽  
...  

Yttrium iron garnet was obtained using four methods of synthesis. A modified citrate method and a modified citrate method with YIG (yttrium iron garnet, Y3Fe5O12) nucleation were used. In two subsequent methods, YIP (yttrium iron perovskite, YFeO3) and α-Fe2O3 obtained in the first case by the citrate method and in the second by precipitation of precursors with an ammonia solution were used as the input precursors for reaction sintering. Differential scanning calorimetry (DSC) measurements of the output powders obtained by all methods allowed to identify the effects observed during the temperature increase. Dilatometric measurements allowed to determine the changes in linear dimensions at individual stages of reaction sintering. In the case of materials obtained by the citrate method, two effects occur with the increasing temperature, the first of which corresponds to the reaction of the formation of yttrium iron perovskite (YIP), and the second is responsible for the reaction of the garnet (YIG) formation. However, in the case of heat treatment of the mixture of YIP and α-Fe2O3, we observe only the effect responsible for the solid state reaction leading to the formation of yttrium iron garnet. The obtained materials were reaction sintered at temperatures of 1300 and 1400 °C. Only in the case of material obtained from a mixture of perovskite and iron(III) oxide obtained by ammonia precipitation at temperature of 1400 °C were densities achieved higher than 98% of the theoretical density. The use of Hot Isostatic Pressing (HIP) in the case of this material allowed to eliminate the remaining porosity and to obtain full density.

1987 ◽  
Vol 22 (11) ◽  
pp. 1475-1482 ◽  
Author(s):  
R.J. Young ◽  
T.B. Wu ◽  
I.N. Lin

Author(s):  
J.Y. Laval

The exsolution of magnetite from a substituted Yttrium Iron Garnet, containing an iron excess may lead to a transitional event. This event is characterized hy the formation of a transitional zone at the center of which the magnetite nucleates (Fig.1). Since there is a contrast between the matrix and these zones and since selected area diffraction does not show any difference between those zones and the matrix in the reciprocal lattice, it is of interest to analyze the structure of the transitional zones.By using simultaneously different techniques in electron microscopy, (oscillating crystal method microdiffraction and X-ray microanalysis)one may resolve the ionic process corresponding to the transitional event and image this event subsequently by high resolution technique.


1997 ◽  
Vol 07 (C1) ◽  
pp. C1-283-C1-286
Author(s):  
P. Novák ◽  
J. Englich ◽  
H. Stepánková ◽  
J. Kohout ◽  
H. Lütgemeier ◽  
...  

1971 ◽  
Vol 32 (C1) ◽  
pp. C1-200-C1-201 ◽  
Author(s):  
P. HANSEN ◽  
W. TOLKSDORF

JETP Letters ◽  
1996 ◽  
Vol 64 (3) ◽  
pp. 171-176 ◽  
Author(s):  
B. A. Kalinikos ◽  
N. G. Kovshikov ◽  
M. P. Kostylev ◽  
H. Benner

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