Phase Transitions in the Brominated Ferroelectric Tris-Sarcosine Calcium Chloride

We demonstrate that the Curie temperature, T-c, of tris-sarcosine calcium chloride can be lowered from 130 K to near 0 K by chemical doping of the anion. In the low temperature limit, quantum fluctuations persist over a range of chemical doping concentrations. Below T-C the temperature dependence of the fractional length change, Delta L/L-o, scales as (Delta L/L-o )(-1) =a broken vertical bar at(lambda) (red line) where t is the reduced temperature, and lambda = -1.5. The behavior of linear coefficient of thermal expansion near T-C is shown in the inset. Three additional phase transitions near 43, 50, and 61 K are resolved.