Comparative study of the structural and magnetic properties of Mn1/3NbS2 and Cr1/3NbS2

Abstract

We compare the magnetism of single crystals of the intercalated transition metal dichalcogenides ${\mathrm{Cr}}_{1/3}\mathrm{Nb}{\mathrm{S}}_{2}$ and ${\mathrm{Mn}}_{1/3}\mathrm{Nb}{\mathrm{S}}_{2}$ using techniques such as dc and ac susceptibility and Lorentz transmission electron microscopy (LTEM). We present a detailed structural investigation of these materials using electron and single-crystal x-ray diffraction measurements to show how substitutional disorder and stacking faults can manifest in ${\mathrm{Cr}}_{1/3}\mathrm{Nb}{\mathrm{S}}_{2}$ and ${\mathrm{Mn}}_{1/3}\mathrm{Nb}{\mathrm{S}}_{2}$, and give rise to additional superlattice reflections in diffraction patterns acquired from ${\mathrm{Mn}}_{1/3}\mathrm{Nb}{\mathrm{S}}_{2}$. Magnetic susceptibility and LTEM measurements show ${\mathrm{Cr}}_{1/3}\mathrm{Nb}{\mathrm{S}}_{2}$ displays chiral helimagnetism below its magnetic ordering temperature (${T}_{\mathrm{C}}$) of 111 K, while there is no evidence that ${\mathrm{Mn}}_{1/3}\mathrm{Nb}{\mathrm{S}}_{2}$ exhibits helimagnetic ordering below its transition temperature ${T}_{\mathrm{C}}=45$ K.