Specific heat and mSR measurements in Gd(hfac)3NITiPr molecular magnetic chains: indications for a chiral phase without long range helical order

Low-temperature specific heat C(T) and zero-field muon spin resonance (μ+SR) 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 λ peak at T0=2.08±0.01 K that disappears upon the application of a 5 T magnetic field. Conversely, the μ+SR data do not present any anomaly at 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 μ+SR 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.