Stabilizing the Tb-based 214 cuprate by partial Pd substitution

TL;DR

This study reports the stabilization of the Tb-based 214 cuprate at ambient pressure through partial Pd substitution, enabling synthesis and detailed characterization of its structure, magnetism, and electronic properties.

Contribution

It introduces a novel method to synthesize Tb-based 214 cuprates at ambient pressure by partial Pd substitution, previously only possible under high pressure.

Findings

Stable at ambient pressure with Pd substitution.

Displays long-range antiferromagnetic order at 7.9 K.

Acts as an n-type semiconductor.

Abstract

Previously known to form only under high pressure synthetic conditions, here we report that the T'-type 214-structure cuprate based on the rare earth atom Tb is stabilized for ambient pressure synthesis through partial substitution of Pd for Cu. The new material is obtained in purest form for mixtures of nominal composition $Tb_{1.96}Cu_{0.80}Pd_{0.20}O_{4}$. The refined formula, in orthorhombic space group Pbca, with a = 5.5117(1) {\AA}, b = 5.5088(1) {\AA}, and c = 11.8818(1) {\AA}, is $Tb_{2}Cu_{0.83}Pd_{0.17}O_{4}$. An incommensurate structural modulation is seen along the a axis by electron diffraction and high resolution imaging. Magnetic susceptibility measurements reveal long range antiferromagnetic ordering at 7.9 K, with a less pronounced feature at 95 K; a magnetic moment reorientation transition is observed to onset at a field of approximately 1.1 Tesla at 3 K. The material is an n-type semiconductor.