  The authors of paper commented claim that trimethylammonium
tetrachlorozincate crystal shows at 282 K the ferroelectric-paraelectric phase
transition. But no ferroelectric hysteresis loop was observed below this
temperature. Moreover, in the low-temperature phase the ferroelectric domain
walls should exist giving dielectric relaxation in a low frequency electric
field. The authors conclude that the phase transition is of the second order.
This conclusion is contrary to the DSC data where the phase transition has a
strong first order character. In the whole measured temperature range the
dielectric loss is 100 times higher than the real part of dielectric constant.
