Crystal growth by Bridgman and Czochralski method of the ferromagnetic quantum critical material YbNi$_4$P$_2$

TL;DR

This paper compares Bridgman and Czochralski crystal growth methods for YbNi$_4$P$_2$, a ferromagnetic quantum critical material, highlighting their effectiveness in producing high-quality single crystals for quantum critical studies.

Contribution

It introduces and compares two crystal growth techniques for YbNi$_4$P$_2$, demonstrating their capabilities to produce high-quality single crystals suitable for quantum critical research.

Findings

Czochralski method yields large, flux-free crystals.

Modified Bridgman method produces needle-shaped crystals.

Crystals have high resistivity ratios indicating good quality.

Abstract

The tetragonal YbNi$_4$P$_2$ is one of the rare examples of compounds that allow the investigation of a ferromagnetic quantum critical point. We report in detail on two different methods which have been used to grow YbNi$_4$P$_2$ single crystals from a self-flux. The first, a modified Bridgman method, using a closed crucible system yields needle-shaped single crystals oriented along the $[001]$-direction. The second method, the Czochralski growth from a levitating melt, yields large single crystals which can be cut in any desired orientation. With this crucible-free method, samples without flux inclusions and a resistivity ratio at 1.8 K of RR$_{1.8\rm K}= 17$ have been grown.