  A new nanoscale ordered perovskite cobaltite, which consists of 90 degree
ordered domains of the layered-112 LaBaCo2O6 has been evidenced by high
resolution- transmission electron microscopy. This new form, like the
disordered La0.5Ba0.5CoO3 and ordered LaBaCo2O6, exhibits a ferromagnetic
transition at TC around 179 K. However, it differs from the two previous forms
by its strong magnetic anisotropy, and correlatively by its high value of
coercivity (0.42 Tesla) at low temperature. We suggest that this behaviour
originates from the locking of magnetic spins in the 90 degree oriented
nano-domain. Moreover, one observes a semi-metal/semi-metal transition at TC
with a maximum magnetoresistance of 6.5 % at this temperature.
