Magnetization, specific heat,
O NMR, and
Np M
ssbauer study of U
Np
O
U
Np
O
の磁化, 比熱,
O NMRおよび
Npメスバウアーによる研究
Martel, L.*; Hen, A.*; 徳永 陽
; Kinnart, F.*; Magnani, N.*; Colineau, E.*; Griveau, J.-C.*; Caciuffo, R.*
Martel, L.*; Hen, A.*; Tokunaga, Yo; Kinnart, F.*; Magnani, N.*; Colineau, E.*; Griveau, J.-C.*; Caciuffo, R.*
U
Np
O
混晶系化合物の磁気,電子状態を磁化,比熱,核磁気共鳴,メスバウアーの各手法を用いて行った。同化合物はT
=17Kで反強磁性に転移する。異なる測定手法を複合的に用いることで、(1)空間的に変調した磁気モーメント、(2)微小なNpモーメントの出現、7.4Kでの比熱の異常などが明らかになった。本結果をもとにUO
とNpO
の特性について議論する。
We report a study of the magnetic and electronic properties of the U
Np
O
solid solution, based on dc- and ac- magnetisation,
Np M
ssbauer spectroscopy,
O Nuclear Magnetic Resonance (NMR), and specific heat measurements. The compound orders antiferromagnetically at T
= 17 K. The different techniques reveal the complexity of this system with:(1) a spatial distribution of ordered moments, (2) a small Np ordered moment, and (3) an additional specific heat anomaly at 7.4 K, with a residual value at very low temperature and a reduced magnetic entropy. The results are compared to the end-members of the series, UO
and NpO
, as well as to the other solid solutions previously reported in this system. We discuss how the properties of U
Np
O
add new input to the trend previously reported for the series, in view of the models that have been previously proposed.