title: The effect of hydrogenation on magnetic interactions in CeNi.
abstract: The crystal structure and magnetic properties of CeNiH(3.7) were studied by means of powder x-ray diffraction, specific heat, and dc and ac magnetization techniques. It was established that hydrogenation stabilizes the 4f(1) state of Ce and turns CeNi-H into a dilute Kondo system with T(K) = 3.7 K. The Kondo screening in CeNiH(3.7) is suppressed by the applied magnetic field, although it still affects the properties of CeNiH(3.7) at 14 T, as indicated by the enhanced γ-coefficient of electronic specific heat, which remains more than twice as large as in the precursor compound CeNi. Its zero-field value is as high as 1890 mJ (mol K(2))(-1). Hydrogenation acts primarily as the negative pressure agent in CeNiH(3.7), while the role of H-metal bonding is secondary.
authors.affiliation: Department of Condensed Matter Physics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, 121 16, Prague 2, Czech Republic. Department of Physics, National University 'Lvivska Polytechnica', Lviv, Ukraine.
authors.forename: A V
authors.initials: AV
authors.lastname: Kolomiets
authors.forename: L
authors.initials: L
authors.lastname: Havela
authors.forename: J
authors.initials: J
authors.lastname: Pospíšil