  The static magnetic and dynamic properties of the compound (NH3)2(CH2)3CoCl4
are investigated in the temperature interval 0.5-50 K. It is shown that at TN
=2.05 K this compound undergoes a transition to a magnetically ordered
antiferromagnet state. A distinctive feature of this compound is the presence
of temperature hysteresis at the transition to the ordered state (corresponding
to a first order magnetic phase transition) and of a spontaneous magnetic
moment along the x axis. The paramagnetic Curie temperatures are determined.
The frequency-field curves of the AFMR spectrum in the xy plane are
investigated at a temperature below TN. The main magnetic parameters of the
biaxial AFM - the value of the low-frequency gap and the effective magnetic
anisotropy field - are determined.
