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

TL;DR

This study investigates the magnetic properties of Gd(hfac)3NITiPr, revealing a chiral phase without long-range helical order through specific heat and muon spin resonance measurements.

Contribution

It provides experimental evidence for a chiral magnetic phase existing without long-range helical magnetic order in a quasi-one-dimensional molecular magnet.

Findings

Specific heat shows a lambda peak at 2.08 K that vanishes under magnetic field.

Muon spin resonance indicates no divergence of correlation functions at transition temperature.

Absence of muon precession suggests no long-range magnetic order.

Abstract

Low temperature specific heat $C(T)$ and zero-field muon spin resonance ($\mu^+$SR) measurements were performed in Gd(hfac)$_3$NITiPr, 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 $T_0$=2.08$\pm$0.01K that disappears upon the application of a 5 Tesla magnetic field. Conversely, the $\mu^+$SR data do not present any anomaly at $T\approx 2$ K, proving the lack of divergence of the two-spin correlation function as required for usual three-dimensional (3D) long range helical order. Moreover, no muon spin precession can be evinced from the $\mu^+$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.