  This is a report on the new 122 ternary transition-metal pnictide of
BaMn2Bi2, which is crystallized from bismuth flux. BaMn2Bi2 adopts
ThCr2Si2-type structure (I4/mmm) with a = 4.4902(3) {\AA} and c = 14.687(1)
{\AA}; it is antiferromagnetic with anisotropic magnetic susceptibility and
semiconducting with a band gap of Eg = 6 meV. Heat capacity result confirms the
insulating ground state in BaMn2Bi2 with the electronic residual Sommerfeld
coefficient of {\gamma} ~ 0. The high temperature magnetization results show
that magnetic ordering temperature is TN ~ 400 K. Hole-doping in BaMn2Bi2 via
potassium in Ba1-xKxMn2Bi2 results in metallic behavior for x = 0.10(1),
0.32(1) and 0.36(1). With K-doping, more magnetically anisotropic behavior is
observed. Although there is a downturn in electrical resistivity and low-field
magnetization data below 4 K in > 30%-doped crystals, there is no sign of zero
resistance or diamagnetism. This manuscript is a report on new materials of
BaMn2Bi2 and Ba1-xKxMn2Bi2 (0 < x < 0.4). Results from powder X-ray
diffraction, anisotropic temperature- and field-dependent magnetization,
temperature-and field-dependent electrical resistivity, and heat capacity are
presented.
