The Photonic Information and Energy Materials Research Center of the Institute of Materials Science and Technology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences has made important progress in the field of new high-temperature and low-pressure superconducting materials. Theoretical predictions indicate that the beryllium-doped methane molecule is a metal at low pressure and has superconductivity. Based on a large number of calculation data, the superconductivity law of beryllium-doped methane molecule is revealed. Related achievements were published in the journal Physical Chemistry Chemical Physics, "Metalization and superconductivity in methane doped by beryllium at low pressure" under the title of "Metalization and superconductivity of beryllium doped methane at low pressure", 2019, DOI : 10.1039 / C9CP06008A).
Methane (CH4), as one of the simplest organic materials, has great potential in the study of superconductors. Methane is composed of very light elements. According to BCS theory, if it can be converted into metal, it will be a potential high-temperature superconductor. However, pure CH4 is a gas under normal pressure and is a wide band gap semiconductor. Even if it is pressurized to 5 million atmospheres, the theory predicts that it is still not in a metallic state. This shows that the transformation of pure CH4 into metals by simple pressurization faces huge challenges.
In order to solve the above problems, Dr. Zhong Guohua and his collaborators of Shenzhen Advanced Institute based on particle swarm optimization, density functional theory and density functional perturbation theory, proposed a new idea to realize the insulator-to-metal transition, that is Miscellaneous metal beryllium.
The researchers considered the crystal structure, electronic state and dynamic properties of beryllium-doped methane molecules and electron-phonon interaction. The results show that BeCH4 with P-1 space group structure can be transformed into a metal state under normal pressure, and a superconducting transition occurs. With the increase of pressure, the maximum superconducting critical temperature can increase the conductivity by nearly 30K.
This shows that electron-doped CH4 is expected to become a new superconductor with both low voltage and high critical temperature. Related research results have systematically revealed the changes of the spatial structure, metal ring and superconductivity of this new superconductor under different pressures, which is of great guiding significance for exploring new high-temperature and low-pressure superconductors.