  We report on the synthesis and physical properties of the new ternary
intermetallic Ce$_2$Rh$_2$Ga. Its formation and dimorphism have been
investigated by powder and single crystal X-ray diffractometry, as well as by
differential thermal analyses. LT- and HT-Ce$_2$Rh$_2$Ga can be obtained by the
chosen respective thermal treatment. The high-temperature form
(HT-Ce$_2$Rh$_2$Ga), stable above 864(5){\deg}C, is orthorhombic La2Ni3-type
[Cmce, oS20, a=5.851(2) {\AA}, b=9.618 (2) {\AA}, c=7.487 (2) {\AA}, V=421.3(2)
{\AA}3]; the low-temperature form (LT-Ce$_2$Rh$_2$Ga), stable below this
temperature, is monoclinic Pr2Co2Al- (Ca2Ir2Si-) type [C2/c, mS20, a=10.0903(6)
A, b=5.6041(3) A, c=7.8153(4) A, beta=104.995(3) degrees, V=426.88(4) A3]. The
magnetic measurements were conducted on two different samples, namely on the
LT-Ce$_2$Rh$_2$Ga and the other on the HT-Ce$_2$Rh$_2$Ga sample. The
HT-Ce$_2$Rh$_2$Ga compound is found to exhibit a phase transition at 128.5 K.
By virtue of the sharp peak anomaly in the temperature dependence of the
magnetic susceptibility this phase transition is plausibly of antiferromagnetic
origin, but occurs at a remarkably high temperature compared to what is typical
for Ce binary and ternary compounds. LT- Ce$_2$Rh$_2$Gaa has a ground state of
ferromagnetic nature which sets in at a paramagnetic-to-ferromagnetic phase
transition at 5.2 K.
