Superconducting material of metal intercalation boron carbon

Abstract

The invention discloses a metal intercalation boron-carbon superconducting material GeB2C2 under normal pressure and a preparation method of the metal intercalation boron-carbon superconducting material GeB2C2. The material has a two-dimensional Kagome lattice structure, the space group is P6 / mmm (No.191), the lattice constants are a = b = 2.732, and c = 16.784. Through calculation and prediction of a first principle, the material has a superconducting transition temperature of about 48 K under a normal pressure (0 GPa) condition, and is dynamically stable. The superconducting mechanism is derived from a strong electroacoustic coupling effect, and the coupling constant lambda is about 1.64. The material is composed of Ge, B and C elements rich in earth crust, the raw materials are easy to obtain, the cost is low, and the large-scale preparation potential is achieved. Compared with a traditional normal-pressure superconducting material, the material disclosed by the invention has a relatively high superconducting transition temperature; compared with a high-voltage superconductor, a high-voltage environment is not needed, and the preparation and application threshold is remarkably reduced. The material can be applied to the fields of high-performance superconducting filters, superconducting nanowire single-photon detectors, small superconducting magnets and the like, and has important scientific research values and good practical application prospects.

Description

Technical Field

[0001] This invention relates to the field of superconducting materials technology, specifically to a metal-intercalated boron-carbon superconducting material with superconducting properties under normal pressure (0 GPa), with the chemical formula GeB2C2. This material was predicted by first-principles calculations to have a superconducting transition temperature of 48 K, and belongs to a novel high-temperature superconducting material. Background Technology

[0002] Superconducting materials, due to their unique properties such as zero electrical resistance and perfect diamagnetism, have broad application prospects in fields such as power transmission, magnetic levitation transportation, magnetic resonance imaging, and quantum communication. Since the discovery of superconductivity in 1911, higher superconducting transition temperatures have been achieved. T c The development of superconducting materials with lower operating pressure has always been a core research direction in this field.

[0003] In recent years, metal-intercalated superconductors have attracted much attention. In 2023, calcium-intercalated bilayer graphene (C2CaC2) achieved a superconducting transition temperature of 18.9 K at ambient pressure; in 2024, calcium-intercalated bilayer silicene (Si2CaSi2) achieved a superconducting transition temperature of approximately 12.5 K at ambient pressure. It is noteworthy that many classic superconducting materials were successfully synthesized experimentally after being predicted through first-principles calculations, which fully demonstrates the important guiding role of theoretical calculations in the development of superconducting materials.

[0004] Although intercalation compounds can achieve superconductivity at ambient pressure, their superconducting transition temperature is typically below 40K, far from meeting the requirements of high-temperature superconductivity in practical applications. This presents a significant obstacle to their practical deployment and device integration.

[0005] First-principles calculations are an effective way to predict novel superconducting materials. Based on density functional theory (DFT) and electro-acoustic coupling theory, the crystal structure, electronic properties, and superconducting characteristics of materials can be predicted before synthesis, providing theoretical support for experimental work.

[0006] Therefore, developing a superconducting material with a high superconducting transition temperature under normal pressure is of great scientific significance and practical application value for promoting the practical application of superconducting technology. Summary of the Invention

[0007] This invention aims to overcome the limitations of existing technologies and provide a novel two-dimensional Kagome lattice metal-intercalated boron-carbon superconducting material, GeB2C2. First-principles calculations predict that this material can achieve a superconducting transition temperature of approximately 48 K at ambient pressure, effectively avoiding the need for high-pressure environments, while also possessing high... T cWith promising practical applications, this invention provides the following technical solution to achieve the above objectives: A metal-intercalated boron-carbon superconducting material with the chemical formula GeB2C2 has the following crystal structure parameters: Space group: 191 (P6 / mmm, hexagonal crystal system) Lattice constants: a = b = 2.732 Å, c = 16.784 Å Unit cell angles: α = β = 90°, γ = 120° Atomic coordinates (fractional coordinates): Ge: (-0.26667, -0.53333, 0.50000) B1: (0.40001, 0.80000, 0.36426) B2: (0.40001, 0.80000, 0.63574) C1: (0.73332, 0.46666, 0.36965) C2: (0.73332, 0.46666, 0.63035) Beneficial effects

[0008] Compared with the prior art, the present invention has the following significant advantages: 1. This material exhibits superconductivity under normal pressure, avoiding the complex equipment required for high-pressure synthesis and operation, significantly reducing preparation and application costs, and enhancing its practical potential; 2. Among atmospheric pressure superconducting materials, the superconducting transition temperature of 48 K is relatively high, superior to that of traditional BCS superconductors, such as MgB2 (39 K); 3. This two-dimensional Kagome layered structure is dynamically stable under normal pressure; 4. The material is composed of three elements: Ge, B, and C. These elements are relatively abundant in the Earth's crust, the raw materials are readily available, and the cost is low, making large-scale production feasible. 5. Based on first-principles calculations, the material exhibits a clear electronic structure and a well-defined superconducting mechanism, providing an accurate and reliable direction for experimental synthesis; 6. It can be applied to high-performance superconducting filters, superconducting nanowire single-photon detectors (SNSPD), miniature superconducting magnets, and other fields. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the structure of the metal intercalated boron-carbon superconducting material GeB2C2 proposed in this invention. Purple represents germanium atoms, green represents boron atoms, and brown represents carbon atoms.

[0010] Figure 2 The diagram shows the electronic density of states of the GeB2C2 superconducting material. The gray area represents the total density of states, while the red, green, and blue curves represent the projected densities of states for germanium, boron, and carbon, respectively.

[0011] Figure 3 This image shows the phonon spectrum and electroacoustic coupling analysis of the GeB2C2 superconducting material. It includes its phonon dispersion curve, phonon density of states, and Eliashberg spectral function. α²F(ω) And the electroacoustic coupling constant λ obtained by this integration. Detailed Implementation

[0012] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The following embodiments are based on first-principles calculations and will help those skilled in the art to further understand the present invention, but do not limit the present invention in any way.

[0013] First-principles calculations based on density functional theory (DFT) were performed using the Quantum ESPRESSO software package, and an ultrasoft pseudopotential was used to describe the electron-ion core interaction. The kinetic energy cutoff for the plane wave basis set was set to 100 Ry, and the charge density cutoff was set to 600 Ry. Self-consistent field (SCF) calculations used a 24×24×1 Monkhorst–Pack k-point grid. Phonon calculations based on density functional perturbation theory (DFPT) used a 6×6×1 q-point grid. In the electron-phonon coupling (EPC) calculations, a double-δ-function broadening method was used for the Brillouin zone integral, with the broadening parameter σ set to 0.002. The results were based on the obtained Eliashberg spectral function. α²F(ω) The electron-phonon coupling constant λ and the logarithmic average phonon frequency were calculated. ω log Superconducting transition temperature ( T c The Coulomb pseudopotential parameter μ* = 0.10 was selected by estimating using the modified McMillan formula by Allen–Dynes.

[0014] like Figure 1 As shown, GeB2C2 has a typical two-dimensional Kagome structure, with purple representing germanium atoms, green representing boron atoms, and brown representing carbon atoms. Boron and carbon atoms construct a Kagome geometric grid in the plane, alternating between triangles and hexagons with shared sides. Germanium atoms serve as intercalation units, located at the center of adjacent Kagome layers, forming a highly symmetrical AA stacking sequence.

[0015] like Figure 2 As shown, the calculated density of states is presented, where the gray curve represents the total density of states, and the red, green, and blue curves correspond to the projected densities of states for germanium, boron, and carbon atoms, respectively. A distinct density of states distribution can be observed at the Fermi level, indicating that the material exhibits metallic electronic characteristics.

[0016] like Figure 3 The phonon dispersion relation, phonon density of states, and Eliashberg spectral function of GeB2C2 are shown. α² F(ω) The curve showing the variation of the electron-phonon coupling integral λ. The phonon dispersion exhibits no imaginary frequency throughout the entire Brillouin zone, confirming the dynamic stability of the structure under ambient pressure. Eliashberg spectral function. α²F(ω) The main peaks are concentrated in the mid-frequency region of 600–800 cm⁻¹, with contributions from this range primarily originating from the vibrational modes of B and C atoms. The calculated electron-phonon coupling constant λ is approximately 1.64, corresponding to a log-average phonon frequency ω. log The superconducting transition temperature is estimated to be 385 K. Using the Allen–Dynes modified McMillan equation and taking the Coulomb pseudopotential parameter μ* = 0.10, the superconducting transition temperature is determined. T c The K value is approximately 48 K. This result indicates that GeB2C2 exhibits significant superconducting properties at ambient pressure, making it a two-dimensional superconducting material with clear research value.

Claims

1. A superconducting material obtained through first-principles calculations and predictions, characterized in that, A novel superconducting material with the chemical formula GeB2C2, intercalated with a metal in a two-dimensional Kagome boron-carbon lattice, is kinetically stable under normal pressure and exhibits superconducting properties.

2. The metal-intercalated boron-carbon superconducting material according to claim 1, characterized in that, The crystal structure parameters of the material are: Space group: 191 (P6 / mmm) Lattice constants: a = b = 2.732 Å, c = 16.784 Å Cell angles: α = β = 90°, γ = 120°.

3. The metal-intercalated boron-carbon superconducting material according to claim 2, characterized in that, The atomic occupancy fraction coordinates of the material are: Ge is located at (-0.26667, -0.53333, 0.50000). B1 is located at (0.40001, 0.80000, 0.36426). B2 is located at (0.40001, 0.80000, 0.63574). C1 is located at (0.73332, 0.46666, 0.36965). C2 is located at (0.73332, 0.46666, 0.63035).

4. The metal-intercalated boron-carbon superconducting material according to any one of claims 1-3, characterized in that, The superconducting transition temperature of the material T c It is approximately 48 K.

5. The application of the metal intercalated boron-carbon superconducting material according to any one of claims 1-4 in the fabrication of superconducting devices.

6. The application according to claim 5, characterized in that, The superconducting devices include superconducting single-photon detectors, superconducting voltage reference devices, superconducting magnetic levitation systems, superconducting radio frequency cavities, superconducting transition edge sensors, superconducting energy storage devices, or superconducting quantum interference devices.

7. The application of the metal intercalated boron-carbon superconducting material according to any one of claims 1-6 in electronic devices operating at temperatures of 48 K and below.

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