Scientific Evolution of Granular Superconductors: A Bibliometric Perspective

Erik Zampieri, Thalita O. R. Rezende, Edimar S. Duran, Rodolfo Izquierdo and Rafael Zadorosny

Departamento de Física e Química, Universidade Estadual Paulista (UNESP), Faculdade de Engenharia, Caixa Postal 31, 15385-000, Ilha Solteira, SP, Brazil.

Abstract

Granular superconductors were first reported in the 1960s, with early studies conducted at Princeton University [1]. Since then, several studies were performed to understand and improve their superconducting properties, as the critical current density. Thus, the present study brings a bibliometric analysis of granular superconductors from 1960 to 2025, based on 14,811 documents retrieved from the Web of Science database.The analysis includes annual scientific production, citation trends, leading journals, institutions, countries, trending topics, and collaboration networks. The results indicate a continuous increase in citations over time, reaching a peak in 2025 (~12,000 citations), while the highest relative growth occurred in 1991. Leading journals include Physical Review,Physica C,Physical Review Letters, Superconductor Science and Technology, and Applied Physics Letters, and prominent institutions include University of Cambridge, National Institute for Materials Science (Japan), University of Tokyo, and Institute of Physics. Conceptual structures were analyzed using keyword co-occurrence, highlighting high-temperature superconductors (e.g., YBCO), microstructural effects, and key properties such as critical current density. In conclusion, the field shows sustained growth and increasing scientific relevance, driven by advances in condensed matter physics and materials science.

Keywords: Bibliometric analysis, Granular superconductors, Superconductivity, Scientific production.

Acknowledgements:
This study was also financed in part by the Coordenação de Aperfeicoamento de Pessoal de Nível Superior-Brasil (CAPES)-Finance Code 001.

[1] Abeles, B., Cohen, R.W., Stowell, R.W.: Phys. Rev. Lett. 18, 902 (1967)