Effect of chiral domain walls on the specific heat of Gd(hfac)(3)NITR (R equals ethyl, isopropyl, methyl, phenyl) molecular magnetic chains

We measured the thermodynamic properties for a class of quasi-one-dimensional (1D) molecular magnets with alternating spins and competing nearest- and next-nearest-neighbor exchange interactions. For the two compounds with higher frustration (R = ethyl and R = isopropyl), which present a genuine 1D magnetic behavior down to the lowest measured temperatures (0.08 and 0.5 K), a peak at T similar or equal to 2 K was observed in the specific heat, and attributed to the excitation of chiral domain walls.