Morphogenetic Study of Particle Domains in Thermoreversible Recording Media Composed of Polymeric Films with Dispersed Fatty Acids

1997 ◽  
Vol 9 (1) ◽  
pp. 91-97 ◽  
Author(s):  
Yoshihiko Hotta ◽  
Tsuguo Yamaoka ◽  
Kunichika Morohoshi
Keyword(s):  
Fatty Acids ◽  
Polymeric Films ◽  
Recording Media ◽  
Morphogenetic Study

Mechanistic Study of Thermoreversible Recording Media Composed of Polymeric Films with Dispersed Fatty Acids

1995 ◽  
Vol 7 (10) ◽  
pp. 1793-1799 ◽  
Author(s):  
Yoshihiko Hotta ◽  
Tsuguo Yamaoka ◽  
Kunichika Morohoshi ◽  
Tetsuya Amano ◽  
Kyoji Tsutsui
Keyword(s):  
Fatty Acids ◽  
Polymeric Films ◽  
Mechanistic Study ◽  
Recording Media

scholarly journals Preparation of Polymeric Films of PVDMA–PEI Functionalized with Fatty Acids for Studying the Adherence and Proliferation of Langerhans β-Cells

ACS Omega ◽  
2020 ◽  
Vol 5 (10) ◽  
pp. 5249-5257 ◽  
Author(s):  
Martha E. Ávila-Cossío ◽  
Ignacio A. Rivero ◽  
Victor García-González ◽  
Manuel Alatorre-Meda ◽  
Eustolia Rodríguez-Velázquez ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Polymeric Films ◽  
Β Cells

Effect of Particle Size and Polarity of Long-Chain Molecules in Polymeric Films on the Supercooling Temperature

1997 ◽  
Vol 9 (4) ◽  
pp. 369-383 ◽  
Author(s):  
Yoshihiko Hotta ◽  
Ryota Hiraoka ◽  
Tsuguo Yamaoka
Keyword(s):  
Particle Size ◽  
Behenic Acid ◽  
Polymeric Films ◽  
The Other ◽  
Recording Media ◽  
Chain Molecules ◽  
Effect Of Particle Size ◽  
Size Of Particles ◽  
Supercooling Temperature ◽  
Long Chain

We studied the effect of particle size and polarity of long-chain molecules on supercooling when dispersed in polymeric films. Supercooling of the molecules of greater than 20 °C, which plays a key role in the thermoreversible response of recording media, was not observed for the molecules alone but occurred only when the molecules formed particles dispersed in a polymer. As the size of particles grew from 0.1–1.0 μm to 3.5 μm, the degree of supercooling of behenic acid dispersed in a copolymer of vinyl chloride and vinyl acetate decreased from 30–40 °C to about 20 °C. The degree of supercooling also decreased from 21–41 °C to 8–17 °C as the polarity of the molecules decreased from fatty acids to fatty alcohols to alkanes. On the other hand, the degree of supercooling increased from 20 °C to 43 °C as the polarity of the polymer matrix increased. This large supercooling effect may be caused by the interaction between the molecules and the polymers which depends on the polarity of both the long-chain molecules and the polymers.

Microstructural characterization of CoPtCr/Cr thin film disks by cross-section TEM and elongated probe micro-diffraction

1991 ◽  
Vol 49 ◽  
pp. 762-763
Author(s):  
M.A. Parker ◽  
K.E. Johnson ◽  
C. Hwang ◽  
A. Bermea
Keyword(s):  
Magnetic Recording ◽  
Electron Probe ◽  
Microstructural Characterization ◽  
Crystallographic Structure ◽  
Recording Media ◽  
Layer By Layer ◽  
Cross Sectional ◽  
New Techniques ◽  
Polished Side

We have reported the dependence of the magnetic and recording properties of CoPtCr recording media on the thickness of the Cr underlayer. It was inferred from XRD data that grain-to-grain epitaxy of the Cr with the CoPtCr was responsible for the interaction observed between these layers. However, no cross-sectional TEM (XTEM) work was performed to confirm this inference. In this paper, we report the application of new techniques for preparing XTEM specimens from actual magnetic recording disks, and for layer-by-layer micro-diffraction with an electron probe elongated parallel to the surface of the deposited structure which elucidate the effect of the crystallographic structure of the Cr on that of the CoPtCr.XTEM specimens were prepared from magnetic recording disks by modifying a technique used to prepare semiconductor specimens. After 3mm disks were prepared per the standard XTEM procedure, these disks were then lapped using a tripod polishing device. A grid with a single 1mmx2mm hole was then glued with M-bond 610 to the polished side of the disk.

Crystallization of barium hexaferrite

1992 ◽  
Vol 50 (1) ◽  
pp. 362-363
Author(s):  
Chung-kook Lee ◽  
Yolande Berta ◽  
Robert F. Speyer
Keyword(s):  
Size Distribution ◽  
Raw Materials ◽  
Barium Hexaferrite ◽  
Recording Media ◽  
Magnetic Recording Media ◽  
Promising Candidate ◽  
Crystallization Method ◽  
Temperature Heat ◽  
High Density Magnetic Recording ◽  
Temperature Heat Treatment

Barium hexaferrite (BaFe12O19) is a promising candidate for high density magnetic recording media due to its superior magnetic properties. For particulate recording media, nano-sized single crystalline powders with a narrow size distribution are a primary application requirement. The glass-crystallization method is preferred because of the controllability of crystallization kinetics, hence, particle size and size distribution. A disadvantage of this method is the need to melt raw materials at high temperatures with non-reactive crucibles, e.g. platinum. However, in this work, we have shown that crystal growth of barium hexaferrite occurred during low temperature heat treatment of raw batches.

Grain separation enhanced magnetic coercivity in Pt/Co multilayers.

1993 ◽  
Vol 51 ◽  
pp. 1038-1039 ◽  
Author(s):  
G.A. Bertero ◽  
R. Sinclair
Keyword(s):  
Remanent Magnetization ◽  
Strong Influence ◽  
Uniaxial Anisotropy ◽  
Magnetic Coupling ◽  
Recording Media ◽  
Magnetic Media ◽  
Signal To Noise ◽  
Out Of Plane ◽  
Longitudinal Recording ◽  
The Relationship

Pt/Co multilayers displaying perpendicular (out-of-plane) magnetic anisotropy and 100% perpendicular remanent magnetization are strong candidates as magnetic media for the next generation of magneto-optic recording devices. The magnetic coercivity, Hc, and uniaxial anisotropy energy, Ku, are two important materials parameters, among others, in the quest to achieving higher recording densities with acceptable signal to noise ratios (SNR). The relationship between Ku and Hc in these films is not a simple one since features such as grain boundaries, for example, can have a strong influence on Hc but affect Ku only in a secondary manner. In this regard grain boundary separation provides a way to minimize the grain-to-grain magnetic coupling which is known to result in larger coercivities and improved SNR as has been discussed extensively in the literature for conventional longitudinal recording media.We present here results from the deposition of two Pt/Co/Tb multilayers (A and B) which show significant differences in their coercive fields.

Structural Investigation of Iron Particles Used for Magnetic Recording Media

1980 ◽  
Vol 38 ◽  
pp. 406-407
Author(s):  
Alfred Baltz
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Structural Investigation ◽  
Magnetic Interaction ◽  
Recording Media ◽  
Magnetic Recording Media ◽  
Recording Medium ◽  
Iron Particles ◽  
Transmission Electron

As part of a program to develop iron particles for next generation recording disk medium, their structural properties were investigated using transmission electron microscopy and electron diffraction. Iron particles are a more desirable recording medium than iron oxide, the most widely used material in disk manufacturing, because they offer a higher magnetic output and a higher coercive force. The particles were prepared by a method described elsewhere. Because of their strong magnetic interaction, a method had to be developed to separate the particles on the electron microscope grids.

Fatty Acids and Glycerides

1979 ◽  
Vol 7 (4) ◽  
pp. 813-814
Author(s):  
J. L. HARWOOD
Keyword(s):  
Fatty Acids
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