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-dime nsional (1D) molecular magnets with alternating spins and competing ne arest- and next-nearest-neighbor exchange interactions. For the two co mpounds with higher frustration (R = ethyl and R = isopropyl), which p resent a genuine 1D magnetic behavior down to the lowest measured temp eratures (0.08 and 0.5 K), a peak at T similar or equal to 2 K was obs erved in the specific heat, and attributed to the excitation of chiral domain walls.