Abstract: An oxide sintered body is obtained by sintering indium oxide, gallium oxide and tin oxide. The oxide sintered body has a relative density of 90% or more and an average grain size of 10 ?m or less. In the oxide sintered body, the relations 30 atomic %?[In]?50 atomic %, 20 atomic %?[Ga]?30 atomic % and 25 atomic %?[Sn]?45 atomic % are satisfied. [In], [Ga] and [Sn] are ratios of contents (atomic %) of indium gallium and tin, respectively, to all metal elements contained in the oxide sintered body. The oxide sintered body has an InGaO3 phase which satisfies the relation [InGaO3]?0.05.

Abstract: Provided is an electrical contact member which is capable of maintaining stable conductivity over a long period of time, while achieving low adhesion to a test subject, in particular, an electrical contact member which is capable of maintaining stable electrical contact over a long period of time by suppressing increase in the contact resistance, while achieving low adhesion to a test subject even after repeated contact at high temperatures around 85° C. or after being left in the atmosphere for a long period of time. The present invention relates to an electrical contact member, which repeatedly comes into contact with a test subject, and wherein the surface of the electrical contact member, said surface coming into contact with the test subject, is configured of a carbon coating film that contains Pd.

Abstract: An oxide sintered body is obtained by sintering indium oxide, gallium oxide and tin oxide. The oxide sintered body has a relative density of 90% or more and an average grain size of 10 ?m or less. In the oxide sintered body, the relations 30 atomic %?[In]?50 atomic %, 20 atomic %?[Ga]?30 atomic % and 25 atomic %?[Sn]?45 atomic % are satisfied. [In], [Ga] and [Sn] are ratios of contents (atomic %) of indium gallium and tin, respectively, to all metal elements contained in the oxide sintered body. The oxide sintered body has an InGaO3 phase which satisfies the relation [InGaO3]?0.05.

Abstract: Provided is an electrical contact member which is capable of maintaining stable conductivity over a long period of time, while achieving low adhesion to a test subject, in particular, an electrical contact member which is capable of maintaining stable electrical contact over a long period of time by suppressing increase in the contact resistance, while achieving low adhesion to a test subject even after repeated contact at high temperatures around 85° C. or after being left in the atmosphere for a long period of time. The present invention relates to an electrical contact member, which repeatedly comes into contact with a test subject, and wherein the surface of the electrical contact member, said surface coming into contact with the test subject, is configured of a carbon coating film that contains Pd.

Abstract: An optical information recording medium of the present invention is a read-only optical information recording medium in which at least one reflective film formed of an Al-based alloy and at least one light transmission layer are successively laminated on a substrate. The arithmetical mean roughness of the reflective film is 0.5 nm or less, and the thickness of the reflective film is 25 nm or more. The optical information recording medium of the present invention is the read-only optical information recording medium including the reflective film which has a high reflectivity and low jitter, preferably has excellent durability, and is used particularly appropriately in an optical disc using a blue laser such as BD-ROM or HD DVD-ROM.

Abstract: Disclosed is a metal oxide-metal composite sputtering target which is useful for the formation of a recording layer for an optical information recording medium, said recording layer containing a metal oxide and a metal. Specifically disclosed is a composite sputtering target containing a metal oxide (A) and a metal (B), wherein the maximum value of the circle-equivalent diameter of the metal oxide (A) is controlled to 200 ?m or less.

Abstract: Provided is an Al-based alloy reflective film which reduces noise on an optical information recording medium by having a reflective film surface accurately reproduce grooves, pits and the like formed on a substrate, and has high reflectivity. A sputtering target which is effective for forming such a reflective film is also provided. The reflective film to be used for the optical information recording medium is substantially composed of an Al-based alloy containing 2.0-15.0 atm % of a rare-earth element, and has a crystallite size of 30 nm or smaller in the thickness direction of the reflective film.

Abstract: An optical recording medium of a pitting recording type, to which recording marks are formed by irradiation with a violet laser beam having a wavelength ? in the range of about 380 to about 450 nm, includes a substrate having a surface provided with guide grooves and lands, and a metal recording layer in which recording marks are formed by irradiation with a laser beam. The guide grooves and the lands meet conditions expressed by: ?/18?DG??/11??(1) 1.5?WG/WL?3.5??(2) Where ? is the wavelength of the laser beam used for writing and reading, DG, is the depth of the grooves, WG is the width of the grooves, and WL is the width of lands formed on the substrate, and the wavelength ? is in the range of 380 to 450 nm.

Abstract: The present invention provides an Ag-based alloy reflective film or semi-transmissive reflective film of an optical information recording medium having high reflectivity and excellent in the wet heat resistance and the light fastness. The invention relates to a reflective film or a semi-transmissive reflective film of an optical information recording medium comprising an Ag-based alloy comprising Hf in an amount of 0.05 to 0.8 atomic %.

Abstract: An optical information recording medium of the present invention is a read-only optical information recording medium in which at least one reflective film formed of an Al-based alloy and at least one light transmission layer are successively laminated on a substrate. The arithmetical mean roughness of the reflective film is 0.5 nm or less, and the thickness of the reflective film is 25 nm or more. The optical information recording medium of the present invention is the read-only optical information recording medium including the reflective film which has a high reflectivity and low jitter, preferably has excellent durability, and is used particularly appropriately in an optical disc using a blue laser such as BD-ROM or HD DVD-ROM.

Abstract: An optical recording medium of a pitting recording type, to which recording marks are formed by irradiation with a violet laser beam having a wavelength ? in the range of about 380 to about 450 nm, includes a substrate having a surface provided with guide grooves and lands, and a metal recording layer in which recording marks are formed by irradiation with a laser beam. The guide grooves and the lands meet conditions expressed by: ?/18?DG??/11 ??(1) 1.5?WG/WL?3.5 ??(2) Where ?is the wavelength of the laser beam used for writing and reading, DG, is the depth of the grooves, WG is the width of the grooves, and WL is the width of lands formed on the substrate, and the wavelength ? is in the range of 380 to 450 nm.

Abstract: Disclosed herein is an optical information recording medium and a recording film for the optical information recording medium, which are capable of readout of short recording marks at a higher C/N ratio than the conventional BD (as in the case of the Super-RENS disk) by means of the same readout power as for the conventional BD, which is lower than that for the Super-RENS disk (or the conventional BD). To be specific, the readout power is 0.3 mW, the short recording marks have a length of 149 nm, and the C/N ratio is no less than 45 dB. The recording film is capable of information recording and reading out to and from recording marks upon irradiation with a laser beam having a wavelength of 380-450 nm, the recording marks including short recording marks having a recording length no longer than 149 nm, and has a refractive index of 1.8-2.5 and an extinction coefficient of 2.3-2.9 both for a laser beam having a wavelength of 380-450 nm.