US 5,582,900 A · Spin-transition compounds and their use for storing, processing and/or displaying information

Abstract

Chemical substances are provided which exhibit thermally induced spin transitions between two stable spin states at ambient temperature, said transitions being associated with a hysteresis phenomenon and resulting in an abrupt variation of the color of the molecules for realizing a medium for storing, processing and/or displaying information by way of thermal writing, optical reading and thermal erasing, a particular embodiment of such a medium comprising at least a layer of chemical substances including a lattice with a molecule comprising a metallic element Fe.sub.(II), or Fe.sub.(III) or Co.sub.(II) associated with at least one ligand chosen from the substituted triazoles which are defined by the formula: ##STR1## in which R is H or an alkyl C.sub.n H.sub.2n+1 or R is an amine group NL.sub.2 where L is H and an alkyl radical, said molecule also comprising one or several anions chosen, for example, from BF.sub.4.sup.-, ClO.sub.4.sup.-, Br.sup.-, Cl.sup.-, and the lattice containing a defined quantity of non-ligand water, ensured by the presence of a hygroscopic substance.

Claims19

Dependent claims

A medium for storing, processing and/or displaying information comprising at least one layer of a chemical substance which exhibits a hysteresis phenomenon, wherein the chemical substance comprises:

(1) a metal-ligand complex having a first at least one ligand of substituted triazoles which are defined by the formula:
##STR4## in which R is selected from the group consisting of an alkyl group and NL.sub.2, wherein L is H or an alkyl group, said metal-ligand complex also comprising at least one anion selected from the group consisting of BF.sub.4.sup.-, ClO.sub.4.sup.-, CO.sub.3.sup.2-, Br.sup.-, and Cl.sup.-,
(2) non-ligand water and
(3) a hygroscopic substance, said hygroscopic substance ensuring the presence of non-ligand water, said medium being addressable, eraseable and re-addressable with data.

1 more element

A medium for storing, processing and/or displaying information comprising a chemical substance which exhibits a hysteresis phenomenon, wherein the chemical substance comprises:

(1) a metal-ligand complex having a first at least one ligand of substituted triazoles which are defined by the formula:
##STR6## in which R is selected from the group consisting of an alkyl group and NL.sub.2, wherein L is H or an alkyl group, said metal-ligand complex also comprising at least one anion selected from the group consisting of BF.sub.4.sup.-, ClO.sub.4.sup.-, CO.sub.3.sup.2-, Br.sup.-, and Cl.sup.- ;
and
(2) non-ligand water, said medium being addressable, eraseable and re-addressable with data.

1 more element

Dependencies are inferred from the claim text.

Spin-transition compounds and their use for storing, processing and/or displaying information

Life of this patent

Spin-transition compounds and their use for storing, processing and/or displaying information

Life of this patent

Abstract

Claims19