Competing Effects in Perovskite Manganites: Ferromagnetism vs. Phase Separation

2000 ◽  
pp. 53-68
Author(s):  
S. Yunoki ◽  
A. Moreo ◽  
E. Dagotto
Keyword(s):  
Phase Separation ◽  
Perovskite Manganites

scholarly journals Effect of the Grain Size on the Magnetic Phase Separation in La0.8Sr0.2MnO3 by Magnetic Force Microscopy

2012 ◽  
Vol 18 (S5) ◽  
pp. 101-102
Author(s):  
P. De Sousa ◽  
N. Panwar ◽  
I. Bdikin ◽  
A. L. Kholkin ◽  
C. M. Fernandes ◽  
...  
Keyword(s):  
Grain Size ◽  
Phase Separation ◽  
Colossal Magnetoresistance ◽  
Room Temperature ◽  
Magnetic Phase ◽  
Magnetic Domain ◽  
Charge Ordering ◽  
Perovskite Manganites ◽  
Fundamental Study ◽  
Metallic Clusters

Perovskite manganites have been the focus of worldwide research during the last two decades because of the observation of colossal magnetoresistance (CMR) effect. These materials have potential applications in magnetic field sensors, spin filters, infrared bolometers and cathodes for solid oxide fuel cells. Such manganites are also important from the fundamental study viewpoint as they offer interplay among various degrees of freedom viz. spin, lattice and charge ordering. Moreover, phase separation may occur in manganites with low concentration of the dopant. In such scenario, ferromagnetic metallic clusters are embedded in antiferromagnetic insulating matrix. The fraction of these magnetic phases may vary from the nano- to micro-scale. With higher dopant concentration, the percolation of these magnetic metallic clusters leads to the apparent CMR effect. In this study we focus our attention to the low doped La0.8Sr0.2MnO3 (LSMO) manganite and investigate the possible magnetic phase separation and effect of variation in grain size on the magnetic domain size. La0.8Sr0.2MnO3 possesses Curie temperature (TC) higher than room temperature, therefore the material is supposed to be in the magnetic state at room temperature.

A possible phase separation scenario observed in perovskite manganites under high pressure

2002 ◽  
Vol 14 (44) ◽  
pp. 11093-11096
Author(s):  
Xin Wang ◽  
Qiliang Cui ◽  
Yuewu Pan ◽  
Guangtian Zou
Keyword(s):  
High Pressure ◽  
Phase Separation ◽  
Perovskite Manganites

The evidence of phase separation in perovskite manganites aboveT c

2004 ◽  
Vol 19 (2) ◽  
pp. 62-63 ◽  
Author(s):  
Hong-wei Tian ◽  
Jian-Feng Zang ◽  
Tao Ding ◽  
Wei-tao Zheng ◽  
Xin Wang
Keyword(s):  
Phase Separation ◽  
Perovskite Manganites

Bulk standards for low-temperature biological x-ray microanalysis

1984 ◽  
Vol 42 ◽  
pp. 282-283
Author(s):  
P. Echlin ◽  
M. McKoon ◽  
E.S. Taylor ◽  
C.E. Thomas ◽  
K.L. Maloney ◽  
...  
Keyword(s):  
Phase Separation ◽  
Low Temperature ◽  
Analytical Method ◽  
Salt Solutions ◽  
Absolute Concentration ◽  
Cooling Process ◽  
X Ray ◽  
The Absolute ◽  
Analytical Procedures ◽  
Electrical Conductors

Although sections of frozen salt solutions have been used as standards for x-ray microanalysis, such solutions are less useful when analysed in the bulk form. They are poor thermal and electrical conductors and severe phase separation occurs during the cooling process. Following a suggestion by Whitecross et al we have made up a series of salt solutions containing a small amount of graphite to improve the sample conductivity. In addition, we have incorporated a polymer to ensure the formation of microcrystalline ice and a consequent homogenity of salt dispersion within the frozen matrix. The mixtures have been used to standardize the analytical procedures applied to frozen hydrated bulk specimens based on the peak/background analytical method and to measure the absolute concentration of elements in developing roots.

Phase separation in sol gel-derived ceramic films of silica-zirconia, alumina-zirconia, and titania-zirconia system

1994 ◽  
Vol 52 ◽  
pp. 646-647
Author(s):  
J. Tong ◽  
L. Eyring
Keyword(s):  
Fracture Toughness ◽  
Phase Separation ◽  
Sol Gel ◽  
Great Influence ◽  
High Strength ◽  
Chemical Durability ◽  
Separation Method ◽  
Toughening Mechanism ◽  
Ceramic Films ◽  
Zirconia Toughened Alumina

There is increasing interest in composites containing zirconia because of their high strength, fracture toughness, and its great influence on the chemical durability in glass. For the zirconia-silica system, monolithic glasses, fibers and coatings have been obtained. There is currently a great interest in designing zirconia-toughened alumina including exploration of the processing methods and the toughening mechanism.The possibility of forming nanocrystal composites by a phase separation method has been investigated in three systems: zirconia-alumina, zirconia-silica and zirconia-titania using HREM. The morphological observations initially suggest that the formation of nanocrystal composites by a phase separation method is possible in the zirconia-alumina and zirconia-silica systems, but impossible in the zirconia-titania system. The separation-produced grain size in silica-zirconia system is around 5 nm and is more uniform than that in the alumina-zirconia system in which the sizes of the small polyhedron grains are around 10 nm. In the titania-zirconia system, there is no obvious separation as was observed in die alumina-zirconia and silica-zirconia system.

Phase separation in fluid additive hard sphere mixtures?

1998 ◽  
Vol 95 (2) ◽  
pp. 131-135 ◽  
Author(s):  
DOUGLAS HENDERSON DEZSO BODA KWONG-YU CHAN
Keyword(s):  
Phase Separation ◽  
Hard Sphere

The plant response to heat requires phase separation

Nature ◽  
2020 ◽  
Vol 585 (7824) ◽  
pp. 191-192 ◽  
Author(s):  
Simon Alberti
Keyword(s):  
Phase Separation ◽  
Plant Response

Smectic a1 ↔ a2 transition of n_c-60.8 : a two-dimensional phase separation of the molecular endgroups

1989 ◽  
Vol 50 (3) ◽  
pp. 375-385 ◽  
Author(s):  
H. Fadel ◽  
D. Guillon ◽  
A. Skoulios ◽  
F. Barbarin ◽  
M. Dugay
Keyword(s):  
Phase Separation ◽  
Two Dimensional

Influence of Polymer Charge, Temperature, and Surfactants on Surface Sizing of Liner and Greaseproof Paper With Hydrophobically Modified Starch

TAPPI Journal ◽  
2009 ◽  
Vol 8 (2) ◽  
pp. 33-38 ◽  
Author(s):  
ANNA JONHED ◽  
LARS JÄRNSTRÖM
Keyword(s):  
Phase Separation ◽  
Contact Angles ◽  
Low Ph ◽  
Hydrophobically Modified ◽  
Paper Sizing ◽  
Surface Sizing ◽  
Separation Temperature ◽  
Hydrophobic Nature ◽  
Sizing Agents ◽  
Charge Temperature

The aim of this study was to investigate the properties of hydrophobically modified (HM) quaterna-ry ammonium starch ethers for paper sizing. These starches possess temperature-responsive properties; that is, gelation or phase separation occurs at a certain temperature upon cooling. This insolubility of the HM starches in water at room temperature improved their performance as sizing agents. The contact angles for water on sized liner were substantially larger than on unsized liner. When the application temperature was well above the critical phase-separation temperature, larger contact angles were obtained for liner independently of pH compared with those at the lower application temperature. Cobb60 values for liner decreased upon surface sizing, with a low pH and high application temperature giving lower water penetration. Contact angles on greaseproof paper decreased upon sur-face sizing as compared to unsized greaseproof paper, independently of pH and temperature. Greaseproof paper showed no great difference between unsized substrates and substrates sized with HM starch at different pH. This is probably due to the already hydrophobic nature of greaseproof paper. However, the Cobb60 values increased at low pH and low application temperature. Surfactants were added to investigate how they affect the sized surface. Addition of surfactant reduces the contact angles, in spite of indications of complex formation.

Ordering, phase separation, and phase transformations in Fe'M alloys

2006 ◽  
Vol 176 (6) ◽  
pp. 611 ◽  
Author(s):  
Yu.I. Ustinovshchikov ◽  
B.E. Pushkarev
Keyword(s):  
Phase Separation ◽  
Phase Transformations
Sign in / Sign up

Export Citation Format

Share Document