  We have measured magnetization M(T,H), electrical resistivity ro(T,H),
thermal conductivity k(T,H), and thermopower S(T,H) of polycrystalline samples
of Nd1-xEuxNiO3; 0 <= x <= 0.35; as a function of temperature and external
magnetic field. The data indicate a metal-insulator transition (MI) in a wide
range of temperature (200 < TMI < 325 K). The magnetic susceptibility X(T)
data, after the subtraction of the rare-earth contribution, exhibit a
Curie-Weiss like behavior at temperatures above TMI. Although a clear
antiferromagnetic AF transition of the Ni sub-lattice is observed at TN <= TMI,
X(T) still increases down to 5 K, suggesting a heterogeneous ground state. The
thermal conductivity of the NdNiO3 compound is not affected by an external
magnetic field of 90 kOe in a wide range of temperature, and its temperature
dependence below 15 K is approximately quadratic, strongly suggesting the
presence of disorder. S(T) is negative above TMI and varies linearly with
temperature. Below TMI, S(T) does not follow the expected behavior of
insulating compounds. There is a minimum close to 120 K, and S(T) changes its
sign at T ~ 30 K, indicating a competition between two types of charge
carriers. A pronounced peak in S(T) at TS ~ 20 K does not follow the expected
phonon-drag temperature dependence either above or below TS and the peak
remains unaltered under magnetic fields up to 90 kOe. However, its magnitude is
enhanced by ~ 25 % with applied magnetic field, exhibiting a clear
magnetothermopower effect. The combined results indicate a coexistence of
ordered and disordered phases below TN and that an applied magnetic field is
suitable for enhancing the thermoelectric properties close to TS.

Strongly Correlated Electrons;Materials Science