PURPOSING AND REPURPOSING A GROUP OF COMPOUNDS THAT CAN BE USED AS HIGH TEMPERATURE SUPERCONDUCTORS

Abstract

This disclosure will describe a novel finding and make the claim for the first time on a group of old compounds and formulated new compounds. These compounds have superconducting property at high temperatures, i.e., 151K or higher. Several compounds were prepared, though not well-purified, at around middle of 1900s. Their chemical, structural, electric and magnetic properties were studied and reported but their superconducting property has not been known and has never been exploited because the idea of type-II superconductivity was not proposed at that time. Consequently, we claim this finding as an invention even though our invention is based on the studies of the compounds' electric and magnetic properties along with their crystallographic features from the previous publications. The experiments to further verify their high temperature superconductivity require the utilization of sophisticated facilities on synthesizing highly pure compounds and the deregulation from government security authorities on purchasing the starting materials.

Claims

1. A group of electrical superconducting materials or compounds with their chemical formulae or compositions written as (M)(X)n, where the M is at least one from the actinide, lanthanide and early transition elements, i.e., actinium (Ac), thorium (Th), protactinium (Pa), uranium (U), Neptunium (Np), plutonium (Pu), americium (Am), curium (Cm), berkelium (Bk), californium (Cf), einsteinium (Es), fermium (Fm), mendelevium (Md), nobelium (No), lawrencium (Lr), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), technetium (Tc), hafnium (Hf), tantalum (Ta) tungsten (W), rhenium (Re) and their isotopes; the X represents at least one element from fluorine (F), chlorine (Cl), bromine (Br), iodine (I), astatine (At), oxygen (0), sulfur (S), selenium (Se), tellurium (Te), nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), carbon (C), silicon (Si), germanium (Ge), boron (B) and their isotopes; and the n is a value ranging from 0.05 to 20;

2. The M and the X for formulae (M)(X)n in claim 1 also contain multiple numbers and/or multiple types of cations (actinide and/or lanthanide and/or early transition metals) and/or multiple numbers and/or multiple types of anions (non-metal), meaning the M in above formulae can also represent the combination of two or more elements and/or numbers from actinide group and/or lanthanide group and/or early transition group listed above in claim 1 while the X can include multiple numbers and/or multiple types anions from the above elemental candidates also in claim 1;

3. The criteria for the materials or the compounds in claim 1 to become a high temperature superconductor for this invention are, firstly, the compounds must match the chemical formulae of (M)(X)n defined in claim 1 with the elements for the M and the X listed in claim 1 to build them using the appropriate n values in the range of 0.05 to 20, and secondly, the compounds must own the property of the co-existence of the electric conductivity and the diamagnetism at 151K or higher, i.e., having superconducting Tc of at least 151K (inclusive), where no stable superconductor that possesses the Tc at atmosphere pressure has been reported to reach this temperature mark heretofore. This means the low temperature end of the superconductors' Tc in this invention is still higher than the highest Tc of current known superconductors while the high temperature end of the superconductors' Tc in this invention has the potential to surpass all the aforementioned milestones;

4. The Tc temperature range for the superconductors in claim 1 can go higher than 151K, meaning the Tc range of this invention is from 151K up to the temperature of the highest Tc of the compound(s) in claim 1. At least the Tc of room temperature was evidenced by the compounds of, but no limited to, ThI.sub.2, ThS, TaC.sub.8, NbC.sub.0.8, Ti(C)n, Zr(C)n, Hf(C)n and probably V(C)n. Therefore, there should be great potential for those compounds and/or their modifications and/or other compounds defined in claim 1 to have the Tc to surpass the room temperature or even the 450K milestones;

5. Even though, the materials or compounds in claim 1 normally have layered molecular configuration connected through repeating structural units or coordination polyhedrons centered by metallic atoms, but this invention has no intention to limit the molecular configuration to only the two dimensional layered type and thus layered linkage is not a criterion for the compounds being the candidate of this disclosure;

6. The superconductors described in claim 1 can be, but not limited, in single crystal, polycrystalline or amorphous, or in bulk, thin film or single molecular layer;

7. The superconductors described in claim 1 should be stable at ambient conditions, meaning there is no need to apply external energy, such as but no limited to, radiation and/or no need to apply external pressure to reach their superconducting states as long as the temperature is below its/their Tc(s).

Description

BRIEF DESCRIPTION OF DRAWINGS

[0028] FIG. 1 displays the history of superconductor development by plotting the advances of the superconducting transition (critical) temperature, Tc, in Kelvin (K) against the time in year.

[0029] FIG. 2A and FIG. 2B exhibit two geometries for the [ThI.sub.6] structural units: (A) Trigonal-antiprismatic (anti-Pris), and (B) Trigonal-prismatic (Pris).

[0030] FIG. 3 highlights the crystallographic unit cell of ThI.sub.2 in a way that two geometries of the [ThI.sub.6] units, i.e., anti-Pris and Pris, are stacked alternatively along c-axis.

[0031] FIG. 4A-4D illustrate the orientations of the atomic geometries for each individual layers along the crystallographic c-axis of the ThI.sub.2 hexagonal unit cell as shown in FIG. 3, where the positions (x, y, z) of thorium (Th) cations are (A) (⅔,⅓,¾); (B) (0, 0, ½); (C) (⅓,⅔,¼); and (D) (0, 0, 0).

[0032] FIG. 5A-5D expand the connections of each layer in FIG. 4A-4D into four unit cells relatively and reveal the layered edge-sharing property of ThI.sub.2. The connections in FIG. 5A and FIG. 5C are easy to see and only the side views are given while the extra top views in FIG. 5B and FIG. 5D are included for better visualizing the edge-sharing features of the 4-cell connections of the four [ThI.sub.6] units.

[0033] FIG. 6 gives a layout of a typical ThS (NaCl structure) and its layer feature on {111} planes is demonstrated, i.e., the thorium cations (Th) and sulfur anions (S) are packed alternatively.

[0034] FIG. 7A reveals the crystal structure of ThS, where the six solid balls, representing sulfur anions (S), are replace by hollow ones, also representing sulfurs, in order to depict the octahedral enclosure of sulfur anions (S) around one thorium cation (Th).

[0035] FIG. 7B is an individual [ThS.sub.6] octahedral structural unit stripped from FIG. 7A.

[0036] FIG. 8 delineates the geometric arrangement of the ThS with the edge-sharing octahedral units of [ThS.sub.6].