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arXiv · 1512.04141

Unusual Behaviour of (Np,Pu)B2C

Tomasz Klimczuk·Pascal Boulet·Jean-Christophe Griveau·Eric Colineau·Ernst Bauer·Matthias Falmbigl·Peter Rogl·Franck Wastin
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Abstract

Two transuranium metal boron carbides, NpB2C and PuB2C have been synthesized by argon arc melting. The crystal structures of the {Np,Pu}B2C compounds were determined from single crystal X-ray data to be isotypic with the ThB2C-type (space group R3m, a = 0.6532(2) nm; c = 1.0769(3) nm for NpB2C and a = 0.6509(2) nm; c = 1.0818(3) nm for PuB2C; Z=9). Physical properties have been derived from polycrystalline bulk material in the temperature range from 2 K to 300 K and in magnetic fields up to 9 T. Magnetic susceptibility and heat capacity data indicate the occurrence of antiferromagnetic ordering for NpB2C with a Neel temperature T_N = 68 K. PuB2C is a Pauli paramagnet most likely due to a strong hybridisation of s(p,d) electrons with the Pu-5f states. A pseudo-gap, as concluded from the Sommerfeld value and the electronic transport, is thought to be a consequence of the hybridisation. The magnetic behaviour of {Np,Pu}B2C is consistent with the criterion of Hill.

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Tomasz Klimczuk, Pascal Boulet, Jean-Christophe Griveau, Eric Colineau, Ernst Bauer, Matthias Falmbigl, Peter Rogl, Franck Wastin. 2015-12-14. Unusual Behaviour of (Np,Pu)B2C. https://doi.org/10.1080/14786435.2015.1009520

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