Statistical model structure of A1-xZxB2 Laves phase C15 system - the superconducting Ce1-xLaxRu2 alloy
B.V. Robouch and A. Marcelli
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati, Via Enrico Fermi 40, I-00044 Frascati, Italy
Dipartimento di Fisica, Universitá di Roma «La Sapienza» P. le Aldo Moro 2, 00185 Roma, Italy
Instytut Fizyki, Universytet Jagiellonski, Reymonta 4, 30-059 Krakow, Poland
Received July 8, 2008
Local structure of Ce1-xLaxRu2 system, measured by EXAFS has been re-examined and correlated to the statistical ad hoc model, recently applied to the sphalerite, wurtzite and other intermetallic ternary alloys. The deconvolution of the EXAFS data show that the Ce1-xLaxRu2 ternary system is essentially a mixture of: CeRu2 and LaRu2 binary alloys with a small proportion of the Ce0.5La0.5Ru2 ternary configuration, being maximum for the intermediate concentration. Moreover, the analysis reveals that while the LaRu2 configuration exhibits a Bernoulli random distribution, the presence of a Ce atom affects both the CeRu2 and Ce0.5La0.5Ru2 distributions, strongly favoring the configuration with the CeCe pair, while keeping rare that with a single Ce ion.