  The interplay between unconventional superconductivity and the ordering of
charge/spin density wave is one of the most vital issues in both condensed
matter physics and material science. The Ti-based compound BaTi_2As_2O, which
can be seen as the parent phase of superconducting BaTi_2Sb_2O, has a layered
structure with a space group P4/mmm, similar to that of cuprate and iron-based
superconductors. This material exhibits a charge density wave (CDW) ordering
transition revealed by an anomaly at around 200 K in transport measurements.
Here, we report the synthesis and systematical study of the physical properties
in Cr-doped BaTi_{2-x}Cr_xAs_2O (x = 0 - 0.154), and demonstrate that the
transition temperature of the CDW ordering is suppressed gradually by the doped
Cr element. The magnetization measurements confirm the evolution of the CDW
ordering transition. These observed behaviors are similar to that observed in
iron-based superconductors, but no superconductivity emerges down to 2 K. In
addition, the first-principles calculations are also carried out for
well-understanding the nature of experimental observations.
