Recording material

A recording material which can be subjected to a reversible phase change, wherein an information can be recorded by causing a desired portion of said recording material to locally have the phase change, characterized in that said material is comprised of an alloy having in its solid crystalline state at least two different crystalline structures, with one of said at least two different crystalline structures existing at a first temperature higher than room temperature and another of said at least two different crystalline structures existing at a second temperature lower than said first temperature but not lower than room temperature, the crystalline structure of the alloy being reversibly changeable by heating;

• further characterized in that the alloy is an alloy that exhibits a quenched crystalline structure, when quenched from said first temperature to the second temperature, which is different than the crystalline structure of said another of said two different crystalline structures, ordinarily exhibited at said second temperature;
• further characterized in that the alloy is an alloy that can have information recorded therein by utilizing the reversible phase change between said one of said at least two different crystalline structures at said first temperature and said another of said at least two different crystalline structures at said second temperature;
• and further characterized in that the alloy is selected from the group consisting of (1) a Cu-based alloy containing, by weight, one of 21-30% of Ga, 20-40% of In, 20-28% of Ge and 16-35% of Sn;
• (2) an Au-based alloy containing, by weight, 2.5-4.0% of Al;
• (3) an Ag-based alloy containing, by weight, at least one of 6-10% of Al, 0.1-10% of Au and 0.1-15% of Cu;
• (4) an Ag alloy containing, by weight, 0.01-2.0% of Al and 43-59% of Cd;
• and (5) an Ag-based alloy containing, by weight, 30-46% of Zn.

A recording material which can be subjected to a reversible phase change, wherein an information can be recorded by causing a desired portion of said recording material to locally have the phase change, characterized in that said material is comprised of an alloy having in its solid crystalline state at least two different crystalline structures, with one of said at least two different crystalline structures existing at a first temperature higher than room temperature and another of said at least two different crystalline structures existing at a second temperature lower than said first temperature but not lower than room temperature, the crystalline structure of the alloy being reversibly changeable by heating;

• further characterized in that the alloy is an alloy that exhibits a quenched crystalline structure, when quenched from said first temperature to the second temperature, which is different than the crystalline structure of said another of said at least two different crystalline structures, ordinarily exhibited at said second temperature;
• further characterized in that the alloy is an alloy that can have information recorded therein by utilizing the reversible phase change between said one of said at least two different crystalline structures at said first temperature and said another of said at least two different crystalline structures at said second temperature;
• further characterized in that the alloy is a Cu-based alloy containing, by weight, 14-16.5% of Al;
• and further characterized in that the material is in a non-bulk form having such a volume that the phase change from one crystalline structure to a different crystalline structure, of said two different crystalline structures, can be locally effected at a desired location when the material is subjected to incident energy.

A recording material which can be subjected to a reversible phase change, wherein an information can be recorded by causing a desired portion of said recording material to locally have the phase change, characterized in that said material is comprised of an alloy having in its solid crystalline state at least two different crystalline structures, with one of said at least two different crystalline structures existing at a first temperature higher than room temperature and another of said at least two different crystalline structures existing at a second temperature lower than said first temperature but not lower than room temperature, the crystalline structure of the alloy being reversibly changeable by heating;

• further characterized in that the alloy is an alloy that exhibits a quenched crystalline structure, when quenched from said first temperature to the second temperature, which is different than the crystalline structure of said another of said two different crystalline structures, ordinarily exhibited at said second temperature;
• further characterized in that the alloy is an alloy that can have information recorded therein by utilizing the reversible phase change between said one of said at least two different crystalline structures at said first temperature and said another of said at least two different crystalline structures at said second temperature;
• and further characterized in that the alloy is a Cu-based alloy containing, by weight, 14-16.5% of Al.