Single crystal growth of CeTAl$_3$ (T = Cu, Ag, Au, Pd and Pt)

TL;DR

This study successfully grew high-quality single crystals of CeTAl$_3$ compounds with various transition metals using optical float zoning, revealing their crystal structures and magnetic properties at low temperatures.

Contribution

It is the first report of single crystal growth for the entire CeTAl$_3$ series with T = Cu, Ag, Au, Pd, Pt, and detailed characterization of their structures and magnetic behaviors.

Findings

CeTAl$_3$ compounds mostly crystallize in a non-centrosymmetric tetragonal structure.

CeAgAl$_3$ adopts an orthorhombic structure, unlike the others.

CeAuAl$_3$, CeCuAl$_3$, and CeAgAl$_3$ show magnetic transitions at low temperatures.

Abstract

We report single crystal growth of the series of CeTAl$_3$ compounds with T = Cu, Ag, Au, Pd and Pt by means of optical float zoning. High crystalline quality was confirmed in a thorough characterization process. With the exception of CeAgAl$_3$, all compounds crystallize in the non-centrosymmetric tetragonal BaNiSn$_{3}$ structure (space group: I4mm, No. 107), whereas CeAgAl$_3$ adopts the related orthorhombic PbSbO$_2$Cl structure (Cmcm, No. 63). An attempt to grow CeNiAl$_3$ resulted in the composition CeNi$_2$Al$_5$. Low temperature resistivity measurements down to $\sim$0.1K did not reveal evidence suggestive of magnetic order in CePtAl$_3$ and CePdAl$_3$. In contrast, CeAuAl$_3$, CeCuAl$_3$ and CeAgAl$_3$ display signatures of magnetic transitions at 1.3K, 2.1K and 3.2K, respectively. This is consistent with previous reports of antiferromagnetic order in CeAuAl$_3$, and CeCuAl$_3$ as well as ferromagnetism in CeAgAl$_3$, respectively.