  The temperature dependences of the Hall-Lorenz numbers (Lxy) in a EuBa2Cu3Oy
(Eu-123) single crystal before and after oxygen reduction are reported. The
study is based on data on the normal state longitudinal and transversal
transport coefficients. Namely, the temperature dependences of the electrical
resistivity, Hall coefficient, longitudinal thermal conductivity, and
transverse thermal conductivity are presented. The set of measurements was
performed for an optimally doped sample (y = 7), then the oxygen content in the
the same crystal was reduced to y = 6.65, and the measurements were repeated.
For both cases Lxy's are about two times larger than the Sommerfeld's value of
the Lorenz number and depend weakly on temperature in a range 300 - 160 K.
Below T = 160 K the Hall-Lorenz number for the optimally doped sample slowly
drops, while the value of Lxy for the oxygen reduced sample begins to rise.
Such results suggest that the electronic system in the investigated compound
may be considered as a metallic one with pseudo-gaps that open at the Fermi
level.
