An information recording medium and a method for producing the same according to the present disclosure are configured to have an information layer in which a larger amount of light for reproduction can be obtained, so that the medium is suitable for recording information at high recording density and is useful for a multi-layer optical disc that records a large amount of contents.

An information recording medium and a method for producing the same according to the present disclosure are configured to have an information layer in which a larger amount of light for reproduction can be obtained, so that the medium is suitable for recording information at high recording density and is useful for a multi-layer optical disc that records a large amount of contents.

A recording medium according to one embodiment of the present disclosure includes a recording layer and an optical thin film. The recording layer includes a heat-sensitive color-developing composition and a photothermal conversion material. The photothermal conversion material absorbs a wavelength in an infrared region and generates heat. The optical thin film is provided on one surface of the recording layer. The optical thin film reflects the wavelength in the infrared region and transmits a wavelength in a visible region.

A recording medium according to one embodiment of the present disclosure includes a recording layer and an optical thin film. The recording layer includes a heat-sensitive color-developing composition and a photothermal conversion material. The photothermal conversion material absorbs a wavelength in an infrared region and generates heat. The optical thin film is provided on one surface of the recording layer. The optical thin film reflects the wavelength in the infrared region and transmits a wavelength in a visible region.

A thin film is provided that primarily comprises titanium oxide and includes Ti, Ag and O. The thin film contains 29.6 at % or more and 34.0 at % or less of Ti, 0.003 at % or more and 7.4 at % or less of Ag, and oxygen as the remainder thereof and has a ratio of oxygen to metals, O/(2Ti+0.5Ag), of 0.97 or more. The thin film has a high refractive index and a low extinction coefficient. In addition, the thin film has superior transmittance, minimally deteriorates in reflectance, and is useful as an interference film or a protective film for an optical information recording medium. The film may also be applied to a glass substrate to provide a heat reflective film, an antireflective film, or an interference filter. A method of producing the thin film is also disclosed.

A thin film is provided that primarily comprises titanium oxide and includes Ti, Ag and O. The thin film contains 29.6 at % or more and 34.0 at % or less of Ti, 0.003 at % or more and 7.4 at % or less of Ag, and oxygen as the remainder thereof and has a ratio of oxygen to metals, O/(2Ti+0.5Ag), of 0.97 or more. The thin film has a high refractive index and a low extinction coefficient. In addition, the thin film has superior transmittance, minimally deteriorates in reflectance, and is useful as an interference film or a protective film for an optical information recording medium. The film may also be applied to a glass substrate to provide a heat reflective film, an antireflective film, or an interference filter. A method of producing the thin film is also disclosed.

The present invention provides a sputtering target which has low risk to the human body, and which is able to be suppressed in the occurrence of a crack even in cases where sputtering is carried out at a high output power for a long period of time.

A sputtering target contains Zn as a main component, contains specific metals including Zr in specific compositions, and contains a complex oxide of Zr.

An information recording medium and a method for producing the same according to the present disclosure are configured to have an information layer in which a larger amount of light for reproduction can be obtained, so that the medium is suitable for recording information at high recording density and is useful for a multi-layer optical disc that records a large amount of contents.

An information recording medium and a method for producing the same according to the present disclosure are configured to have an information layer in which a larger amount of light for reproduction can be obtained, so that the medium is suitable for recording information at high recording density and is useful for a multi-layer optical disc that records a large amount of contents.

A dielectric layer is formed from an oxide containing Sn and at least one of Zn, Zr, Si and Ga. The molar percentages of Sn, Zn, Zr, Si, and Ga, relative to the total elements in the oxide, represented by a, b, c, d, and e, respectively, satisfy the conditions (1)-(7): (1) 0≤b/(a+b)≤0.6, (2) 0≤(c+d)/(a+b+c+d+e)≤0.5, (3) 0≤b≤50, (4) 0≤c≤40, (5) 0≤d≤45, (6) 0≤e≤40, and (7) 20≤b+c+d+e≤80. The dielectric layer enables favorable information recording in an oxide-based recording layer on which the dielectric layer is directly overlaid, does not require preventive measures for health hazard, and is superior in durability.