When Nagamatsu et al. announced the
discovery of superconductivity in magnesium diboride (MgB2)
in the journal Nature in March 2001, it launched yet another
superconductivity revolution. Here was a surprisingly simple and
inexpensive compound, one that had been commonly used in chemistry
labs for half a century, that remains superconductive at temperatures
as high as 39 degrees Kelvin. The MgB2 transition
temperature is a record high for simple metallic compounds, and the
discovery opened up the possibility of a new class of low-cost
high-performance superconductive materials. The list of top 25 papers
is headed by the March 1 2001 Nature article by Nagamatsu et
al. announcing the discovery. The top 25 is dominated by reports
examining the superconductive, thermodynamic, electronic, and photonic
properties and behavior of MgB2 using a wide variety of
analytical technologies. The top 25 also include discussions of
methods for possibly achieving higher transition temperatures while
improving the maximum current and magnetic field in MgB2,
and the prospects for applications. Other highly cited papers examine
the mechanism of superconductivity in MgB2 and its fit with
the Bardeen-Cooper-Schrieffer model of superconductivity. A final area
of note in the top 25 concerns papers that discuss the preparation of
MgB2 as pellets, thin filaments, and dense wires, and the
properties of the material in each format.
Methodology
To construct this database,
papers were extracted based on title- and author-supplied keywords for
Magnesium Diboride Superconductors. The keywords used were as
follows:
The baseline time span for this database
is 1992 - May 2002. The resulting database contained 438 papers; 1,331 authors;
44 countries; 63 journals; and 309 institutions.
Rankings
Once the database was in place,
it was used to generate the lists of top 25 papers, authors, journals,
institutions, and nations, covering the time span of 1992 - May 2002.
The top 25 papers are ranked according to total cites. Rankings for author, journal, institution, and country are listed in three ways: according to total cites, total papers, and total cites/paper. The paper thresholds used to determine scientist, institution, country, and journal rankings according to total cites/paper were as follows: 6, 5, 2, and 1, respectively.
