FePt nanoparticle formation with lower phase transition temperature by single shot plasma focus ion irradiation

Hydrothermally synthesized one-dimensional and two-dimensional nanocrystals of VO2 undergo phase transition around 65?C, where temperature and mechanism of phase transition are dependent on dimensionality of nanocrystals. Both nanocrystalline samples exhibit depression of phase transition temperature compared to the bulk material, the magnitude of which depends on the dimensionality of the nanocrystal. One-dimensional nanoribbons exhibit lower phase transition temperature and higher values of apparent activation energy than two-dimensional nanosheets. The phase transition exhibits as a complex process with somewhat lower value of enthalpy than the phase transition in the bulk, probably due to higher proportion of surface atoms in the nanocrystals. High values of apparent activation energy indicate that individual steps of the phase transition involve simultaneous movement of large groups of atoms, as expected for single-domain nanocrystalline materials.

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Lower phase transition temperature of solid hydrogen sulphide

Czechoslovak Journal of Physics ◽

10.1007/bf01690976 ◽

1972 ◽

Vol 22 (7) ◽

pp. 617-620

Author(s):

A. S. Farghaly

Keyword(s):

Phase Transition ◽

Transition Temperature ◽

Phase Transition Temperature ◽

Hydrogen Sulphide ◽

Solid Hydrogen ◽

Lower Phase

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Lower phase transition temperature of solid hydrogen sulphide

Vacuum ◽

10.1016/0042-207x(73)91144-5 ◽

1973 ◽

Vol 23 (4) ◽

pp. 154

Keyword(s):

Phase Transition ◽

Transition Temperature ◽

Phase Transition Temperature ◽

Hydrogen Sulphide ◽

Solid Hydrogen ◽

Lower Phase

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Synthesis of Nanogels of Poly Methyacrylic Acid Using Methyl Cellulose as a Template

Materials Science Forum ◽

10.4028/www.scientific.net/msf.787.401 ◽

2014 ◽

Vol 787 ◽

pp. 401-406

Author(s):

Jun Li Zhang ◽

Peng Wang ◽

Dong An ◽

Xue Ting Li ◽

Qian Wu ◽

...

Keyword(s):

Phase Transition ◽

Transition Temperature ◽

Phase Transition Temperature ◽

Methacrylic Acid ◽

Aqueous Media ◽

Polymer System ◽

Methyl Cellulose ◽

Solution Temperature ◽

Lower Phase ◽

Lower Temperature

In recent decades, thermo sensitive polymer system has been intensively studied due to significant importance in fundamental studies and various applications. Methyl cellulose (MC) is a thermo sensitive natural polymer, having a phase transition temperature or a lower critical solution temperature of about 65 °C. When methacrylic acid (MAA) was added to the MC solution, the phase transition of MC occurred at a lower temperature less than 65°C, and a higher concentration of MAA leds to a lower phase transition temperature of MC. Based on the phase transition of MC solution triggered by MAA, the surfactant-free poly (methacrylic acid) nanogels were synthesized by using methyl cellulose as a template in an aqueous media. The resulting PMAA nanogels characterized by using dynamic light scattering (DLS) and Fourier Transform Infrared Spectroscopy (FTIR). The nanogels of poly methyacrylic acid (PMAA) were affected by the concentration of both MC and MAA. A higher concentration of MAA led to a higher polymerization rate, and the higher concentration of MC resulted in the formation of the samller size of PMAA nanogels.

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STUDY THE POLYOL PROCESS OF PREPARING THE Ru DOPED FePt NANOPARTICLES

International Journal of Modern Physics B ◽

10.1142/s0217979209062979 ◽

2009 ◽

Vol 23 (17) ◽

pp. 3561-3566

Author(s):

CHIH-HAO LEE ◽

JEN-HO HSU ◽

HUI-CHIA SU ◽

TZU WEN HUANG

Keyword(s):

Phase Transition ◽

Particle Size ◽

Transition Temperature ◽

Phase Transition Temperature ◽

Shell Structure ◽

Polyol Process ◽

Fept Nanoparticles ◽

Fept Alloy ◽

Fept Nanoparticle ◽

The One

The structure of Ru doped FePt nanoparticles using polyol process was studied. The particle size grown is around 5 nm, and a shell structure might be formed. By selecting the time and temperature of adding the Ru precursors into solution, three different processes to synthesize the FePtRu particles were studied resulting in different growing mechanics. The possible models during the reaction process are also discussed. The phase transition temperature for the as-grown FCC FePt nanoparticle to transform into L 10 FePt nanoparticle is about 823 K which is about the same as the one without doping Ru atoms. From the XAS study of each element, the possible scenario is that: although Ru atoms with the size close to the Pt , they do not totally replace the Pt sites in the FePt alloy. Instead, most of Ru formed a shell outside the FePt nanoparticles and Fe atoms are replaced.

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The structure of membranes and membrane proteins embedded in amorphous ice

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100122563 ◽

1992 ◽

Vol 50 (1) ◽

pp. 432-433

Author(s):

Uwe Lücken ◽

Joachim Jäger

Keyword(s):

Phase Transition ◽

Transition Temperature ◽

Membrane Proteins ◽

Phase Transition Temperature ◽

Lipid Vesicles ◽

Freezing Stress ◽

Amorphous Ice ◽

Different Temperatures ◽

Band Pass ◽

Lipid Polymorphism

TEM imaging of frozen-hydrated lipid vesicles has been done by several groups Thermotrophic and lyotrophic polymorphism has been reported. By using image processing, computer simulation and tilt experiments, we tried to learn about the influence of freezing-stress and defocus artifacts on the lipid polymorphism and fine structure of the bilayer profile. We show integrated membrane proteins do modulate the bilayer structure and the morphology of the vesicles.Phase transitions of DMPC vesicles were visualized after freezing under equilibrium conditions at different temperatures in a controlled-environment vitrification system. Below the main phase transition temperature of 24°C (Fig. 1), vesicles show a facetted appearance due to the quasicrystalline areas. A gradual increase in temperature leads to melting processes with different morphology in the bilayer profile. Far above the phase transition temperature the bilayer profile is still present. In the band-pass-filtered images (Fig. 2) no significant change in the width of the bilayer profile is visible.

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