Specific Heat and Muon Spin Resonance Measurements in Gd(hfac)3NITiPr Molecular Magnetic Chains: Indications for a Chiral Phase without Long-range Helical Order

Low-temperature specific heat and zero-field muon spin resonance measurements were performed in Gd(hfac)3NITiPr, a quasi-one-dimensional molecular magnet with competing nearest-neighbor and next-nearest-neighbor intrachain exchange interactions. The specific heat data exhibit a lambda-peak at T=2.08 K that disappears upon the application of a 5-tesla magnetic field. Conversely, the muon spin resonance data do not present any anomaly in the neighbor of T=2 K, proving the lack of divergence of the two-spin correlation function as required for usual three-dimensional long-range helical order. Moreover, no muon spin precession can be evinced from the muon asimmetry curves, thus excluding the presence of a long-range-ordered magnetic lattice. These results provide indications for a low-T phase where chiral order is established in absence of long-range helical order.