Magnetic and Electronic Properties of NpFeGa5

NpFeGa5 single crystals prepared by the Ga-flux method have been investigated by magnetization, specific heat and 237Np Mössbauer spectroscopy measurements. An antiferromagnetic (AF) transition has been observed at TN ~ 114 K. The second AF transition which takes place at T* ~ 74 K has only been detected in the magnetization data. A saturated ordered Np moment of 1.00(5)µB and the occurrence of a Np3+ charge state were inferred from the Mössbauer data. The angle between the Np ordered moment and the basal plane was shown to be ~ 17°, in good agreement with the value observed by neutron diffraction in the low temperature AF phase. The absence of change of the quadrupole interaction parameters at T* did not allow to gain information on the Np moment reorientation at T*. The trend of the isomer shift along the NpTGa5 series and the discrepancy between the Np moments determined by neutron diffraction and Mössbauer spectroscopy indicated a partial spatial delocalization of the 5f-electrons in NpFeGa5.

SANCHEZ J.P.;  AOKI Dai;  ELOIRDI Rachel;  GACZYNSKI Piotr;  GRIVEAU Jean-Christophe;  COLINEAU Eric;  CACIUFFO Roberto; 

2011-11-11

IOP PUBLISHING LTD

JRC64648

0953-8984,   

http://iopscience.iop.org/0953-8984/23/29/295601/,    https://publications.jrc.ec.europa.eu/repository/handle/JRC64648,   

10.1088/0953-8984/23/29/295601,