Comment on "Synthesis of Ultra-Incompressible Superhard Rhenium Diboride at Ambient Pressure"
Natalia Dubrovinskaia,1,2*
Leonid Dubrovinsky,3
Vladimir L. Solozhenko4
Chung
et al. (Reports, 20 April 2007, p. 436) reported the synthesis
of superhard rhenium diboride (ReB
2) at ambient pressure. We
show that ReB
2, first synthesized at ambient pressure 45 years
ago, is not a superhard material. Together with the high cost
of Re, this makes the prospect for large-scale industrial applications
of ReB
2 doubtful.
2 Lehrstuhl für Kristallographie, Physikalisches Institut, Universität Bayreuth, 95440 Bayreuth, Germany.
3 Bayerisches Geoinstitut, Universität Bayreuth, 95440 Bayreuth, Germany.
4 Laboratoire des Propriétés Mécaniques et Thermodynamique des Matériaux, Centre National de la Recherche Scientifique, Université Paris Nord, 93430 Villetaneuse, France.
* To whom correspondence should be addressed. E-mail natalia.dubrovinskaia{at}min.uni-heidelberg.de
