A recording member in which a bismuth-antimony alloy thin film containing antimony as its indispensable component is deposited on a predetermined substrate is disclosed. The Sb content of the film lies in a range of from 1 % to 15 % inclusive in terms of the average atomic-%. Preferably, the Sb content has the average value held in the specified range, and it is gradually increased in the thickness direction of the film so that in the part near the substrate and/or front surface of the film, the maximum content may lie within a range of at most three times the average content of other part of the film.

An optical recording structure layer has an optical reflecting layer, a phase layer on the reflective layer, an active layer on the phase layer and a matrix layer on the active layer. The phase layer and matrix layer are substantially transparent to radiation. A thin metal layer on the matrix layer has a thickness from 20 to 100 Angstroms to achieve a relatively constant absorption and reflection characteristics for the structure over a broad band of radiation.

A light information recording medium is disclosed. The medium is comprised of a support which has transparency with respect to light. The support has coated thereon a light sensitive recording layer which contains SiO.sub.2 and In at the SiO.sub.2 content of 10 to 35 vol. % based on the total volume of SiO.sub.2 and In. The recording medium can be used for the recording and reading of the information recorded thereon by striking the medium with laser light from the support side. The recording medium can be used as an optical disk memory having excellent recording sensitivity with respect to laser light, long preservability and high resolving power as well and high S/N ratio.

An optical recording medium is composed of a substrate, a recording layer containing an inorganic material which includes as the main component a sulfide of at least one element selected from the group consisting of the elements of IIb, IIIb, IVb, Vb, and VIb groups, which is formed on the substrate, with a complex index of refraction of (n-ik), where n.gtoreq.1.8, and k.ltoreq.0.3, and a reflection layer formed on the recording layer. In this invention, an intermediate layer can be interposed either between the substrate and the recording layer, or between the recording layer and the reflection layer.

A recording medium comprising a substrate and a recording layer arranged on the substrate, said recording layer being removable by irradiation of radiation having high energy density thereto through evaporation or fusion in the area having received said irradiation, which is characterized in that said recording layer comprises indium and at least one metal compound selected from the group consisting of a metal sulfide, a metal fluoride and a metal oxide and contains at least one metal showing a surface tension of not less than 600 dyne/cm within temperatures of the melting point thereof to a temperature higher than the melting point by 300.degree. C.