Optical recording materials

Among all semiconductor NPs, metal selenides have been the focus of great attention due to their importance in various applications such as thermoelectric cooling materials, optical filters and sensors, optical recording materials, solar cells, superionic materials, laser materials and biological labels. Many synthetic methods have been developed for the preparation of relatively monodispersed selenide nanopartides (Murray et al., 1993 Korgel... 

Optical recording material with Laser-writing and Laser-reading capabilities consists of the metal complex 48 [91 JAP(K)0313384]. 

An optical recording material that is an analogue of 48 but with fusion of the pyrido[3,2-c][ 1,2,4]triazine type was also reported [91JAP(K)0313384]. 

TABLE I. Typical Requirements of the Optical Recording Material... 

The great merit of thermal irreversibility is the permanent nature of the states. Therefore, fulgides have long been viewed as potential candidates for photon-mode optical recording materials. In addition, fulgides have been used as prototypes to demonstrate their potential applicability as photoswitchable functional materials. Those switch models that had appeared up until the end of 1999 are described in this chapter. 

Infrared dyes include indoleninecyanines and azulenium compounds, both of which are used in optical recording materials.46 Other examples are metal (Mn, Fe, Co, Cd, Al, Cu, Pd)-complexed phthalocyanines, quinones, quinonoids, and imminium and diiminium compounds (Fig. 13.37). 

A highly efficient photochromic process is essential for organic photochromic compounds used as optical recording materials.39,40 That means that the quantum yields for the photocoloring and bleaching reactions should be high, but the quantum yield for the side reactions should be as low as possible. In order to solve the problems mentioned earlier, extensive studies have been carried out, and some promising results have been obtained so far. 

A. P. Glaze, H. G. Heller, and J. Whittall, Photochromic heterocyclic fulgides. Part 7. (E)-Adamantylidene-[1 -(2,5,-dimethyl-3-furyl)ethylidene] succinic anhydride and derivatives Model photochromic compounds for optical recording materials, J. Chem. Soc., Perkin. Trans. 2, 1992, 591-594. 

Zinc selenide (yellow) and telluride (brown) have similar stractures to those of the sulfide, both existing in both wurtzite and zinc blende modifications. The selenide is used with zinc sulfide as a phosphor. It has the interesting property that it can act as a bine-green solid state laser bine-green laser action in solids is rare (most solid-state lasers function towards the red end, 635 nm or more, of the spectrum). At room temperature, laser action with the selenide at a wavelength of 525 nm (green) is observed and at -196°C at 495 nm (bine). Unfortunately the laser is relatively short-lived. Zinc telluride is a wide band gap semicondnctor whose electron transport properties in the form of thin films of stoichiometric and nonstoichiometric forms have been mnch studied. Its applications in optoelectronics, for example, as an optical recording material, have been reviewed. ... 

Fulgides and related diarylethenes have been investigated extensively because of the long-term thermal stability of their photocyclized colored forms, which could lead to this application in erasable optical recording materials and photoswitchable optical elements. The entrapment of these photochromic molecules in polymer films is necessary for these practical applications. Picosecond laser photolysis was employed to study the electrocyclic reaction of a furylfulgide (18, Figure 8) in polymer solids and revealed that the colored structure was formed with a time constant of ca. lOps irrespective of the nature of the polymer matrix.49... 

Y. Kawanishi and K. Ichimura, Photochromic optical recording materials in liquid crystalline media, Nippon Shashin Gakkaishi 57, 413-418 (1989). 

Hansen, P. (1990). Magneto-optical recording materials and technology. 

F.H. Kreuzer, Ch. Brauchle, A. Miller, A. Petri, Cyclic Liquid-Crystalline Siloxanes as Optical Recording Materials, in [48]. 

Morinaka, A. Oikawa, S. Optical recording materials. Jpn. Kokai Tokkyo Koho JP 60219647, 1985 Chem. Abstr. 1986,104, 159715. 

Magneto-optical media An optical recording material in which marks are recorded using a thermomag-netic process. That is, the material is heated until the magnetic domains can be changed by the application of a modes magnetic field. This material is rewritable. 

Phase-change media An optical recording material consisting of an alloy that has two metastable phases with different optical properties. Phase-change media can be rewritable or write-once. 

Park, J. Kim, MR. Choi, W.S. Seo, H. Yeon, C. (1999). Characterization of Amorphous Phases of Ge2Sb2Tes Phase-change Optical Recording Material on Their Crystallization Behavior. Japanese Journal of Applied Physics, Vol.38, No.8B, (August 1999), pp. 4775-4779, ISSN 0021H922... 

Stegmaier, R, De Girolamo Del Mauro, A., Venditto, V, Guerra, G. Optical recording materials based on photoisomerization of guest molecules of a polymeric crystalline host phase. Adv. Mater., 17,1166-1168 (2005). 

Industrial Applications Solar cells plasma dis-play panel antireflective coatings chemical mechanical polishing optical recording materials inks paints adhesives thermoplastics detergents textiles wood " ... 

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