  We report that the major features in the temperature dependence of dc and ac
magnetization of a well-known spin-chain compound, Ca3Co2O6, which has been
known to exhibit two complex magnetic transitions due to geometrical
frustration (one near 24 K and the other near 10 K), are found to be
qualitatively unaffected in its nano form synthesized by high-energy
ball-milling. However, the multiple steps in isothermal magnetization - a topic
of current interest in low-dimensional systems - known for the bulk form well
below 10 K is absent in the nano particles. We believe that this finding will
be useful to the understanding of the 'step' magnetization behavior of such
spin-chain systems.
