Delocalization of the U 5f magnetic moments in U(In_0.6Sn_0.4)₃and UNiSn under high pressure

Abstract

The pressure-temperature dependence of the electronic and magnetic properties of the compounds U(In 1−x Sn x ) 3 and UNiSn has been investigated by means of high pressure x-ray diffraction, 119 Sn nuclear forward scattering (NFS) of synchrotron radiation and Mössbauer spectroscopy (MS) measurements. We show that pressure has different effects on these systems: while U(In 0.8 Sn 0.2 ) 3 shows some of the typical properties of nearly localized 5f systems, pressure induces the delocalization of the U 5f electrons in U(In 0.6 Sn 0.4 ) 3 and UNiSn with a pressure dependent interplay between RKKY exchange interaction and the consequent collapse of the magnetic order. These results are discussed in terms of hybridization between U 5f electrons and conduction band electrons such as U 6d, Sn/In 5sp and Ni 3d electrons.

Geophysical applications of nuclear resonant spectroscopy

“…The measurement and analysis of such time spectra constitute the main part of the SMS method. Dur ing the last decade, we saw the refinement of the SMS technique and its application in the area of high-pressure research (Nasu, 1994(Nasu, , 1998Zhang et al, 1999;Pleines et al, 1999;Lubbers et al, 1999b;Lin et al, 2004a;Barla et al, 2004aBarla et al, , 2004bBarla et al, , 2005aBarla et al, , 2005bJackson et al, 2005a).…”

“…The straight line indicates identical temperatures. 57Fe isotope (Nasu, 1998;Lubbers et aL, 1999aLubbers et aL, , 1999bLubbers et aL, , 2000bRupprecht et aL, 2000;Wortmann et al, 2002;Lin et aL, 2004a;Mao et al, 2004b), the l5lEu isotope (Lubbers et al, 1999a;Lengsdorf et al, 2004), the 119Sn isotope (Barla et al, 2005a), and the 149Sm isotope (Barla et aL, 2004a(Barla et aL, , 2004b(Barla et aL, , 2005b. Geophysi cal applications of the SMS method examined the pressure dependence of magnetism in materials like Fe3S (Lin et aL, 2004a) or FeH^ .…”