We investigate a hexagonal ${\mathrm{ScAl}}_3{\mathrm{C}}_3$-type antiferromagnet ${\mathrm{GdZn}}_3{\mathrm{P}}_3$ single crystal. Compared with antiferromagnetic topological material ${\mathrm{Eu}\mathit{M}}_2{X}_2$ $(M=\mathrm{Zn}, \mathrm{Cd}; X=\mathrm{P}, \mathrm{As})$, the ${\mathrm{GdZn}}_3{\mathrm{P}}_3$ features an additional ${\mathrm{ZnP}}_3$ trigonal planar units. Notably, single-crystal x-ray diffraction analysis reveals that Zn and P atoms within a trigonal planar layer exhibit significant anisotropic displacement parameters with space group $P{6}_3/mmc$. Meanwhile, a scanning transmission electron microscopy experiment demonstrates the presence of interstitial P atoms above and below the ZnP honeycomb lattice, suggesting potential ZnP bond instability within the ${\mathrm{ZnP}}_3$ trigonal layers. Concerning the triangular $\mathrm{G}{\mathrm{d}}^{3+}$ layer, the magnetic susceptibility χ(T) and heat capacity measurements reveal an A-type antiferromagnetic order at $T_N=4.5\mathrm{K}$. Below $T_N$, the in-plane χ(T) is nearly 4 times the χ(T) along $c$ axis, indicative of strong magnetic anisotropy for salt-flux-grown ${\mathrm{GdZn}}_3{\mathrm{P}}_3$ crystal. The density function theory calculation shows that ${\mathrm{GdZn}}_3{\mathrm{P}}_3$ is an indirect semiconductor with a band gap 0.27 eV, supported by the resistivity measurement on the polycrystal sample. Interestingly, Hall measurements of metallic ${\mathrm{GdZn}}_3{\mathrm{P}}_3$ crystals grown via salt flux reveal a low concentration of hole carriers, consistent with the previously mentioned presence of interstitial P atoms. Furthermore, these crystals exhibit a pronounced nonlinear anomalous Hall effect below $T_N$. In contrast, ${\mathrm{GdZn}}_3{\mathrm{P}}_3$ crystals grown by chemical vapor transport display weak semiconducting behavior. Despite exhibiting a similar $T_N$, the in-plane χ(T) below $T_N$ in the vapor-transport-grown crystal is approximately half in magnitude compared to that of the salt-flux-grown sample, which supports the hypothesis of charge carrier-mediated Ruderman-Kittel-Kasuya-Yosida interactions. These findings collectively establish ${\mathrm{GdZn}}_3{\mathrm{P}}_3$ as a compelling model system for investigating the coupling between charge carriers and triangular lattice magnetism within a two-dimensional framework.

Close

PrevNext

View figure in article

• Antiferromagnets
• Rare-earth magnetic materials
• Triangular lattice
• Density functional theory
• Magnetization measurements
• Resistivity measurements
• Scanning electron microscopy
• Specific heat measurements
• Susceptibility measurements
• X-ray diffraction