SAIP2023

Investigation of the novel tetragonal compounds Ba$T_{2}$P$_{2}$($T$ = Co, Ru, Pd)

4 Jul 2023, 11:00

20m

University of Zululand

Oral Presentation Track A - Physics of Condensed Matter and Materials Physics of Condensed Matter and Materials Track 2

Speaker

Arthur Van der Spuy (University of the Witswatersrand)

Description

Tetragonal $A$Co$_2$$Pn_2$ ($A$: alkali or alkaline earth metals, $Pn$: pnictides) compounds are known for their exotic structure-property relationships [1-4]. Some of these compounds have also been reported to exhibit unusual behaviors, like the recently observed positive curvature in electrical resistivity of highly pure single crystals of $K$Co$_2$$As_2$ [5]. In the present work, we investigate the structural, magnetic, transport and thermal properties of polycrystalline samples of unexplored materials Ba$T_{2}$P$_{2}$ ($T$ =Co, Ru, Pd). Our study confirms that BaCo$_{2}$P$_{2}$ and BaRu$_{2}$P$_{2}$ crystallize with ThCr$_2$Si$_2$-type tetragonal structures while BaPd$_{2}$P$_{2}$ crystallizes with a CeMn$_2$Si$_2$-type tetragonal structure. All three compounds show metallic behavior and sizable density of states of conduction carriers at the Fermi level and do not exhibit any phase transition down to the lowest temperature of our measurements. We attempt to model the physical properties data of these compounds as well as explore the effect of lowering the crystal symmetry, if any. The experimental results will be discussed in detail and compared with the existing literature.

References

[1] A. Pandey, D. G. Quirinale, W. Jayasekara, et al., Crystallographic, electronic, thermal, and magnetic properties of single-crystal SrCo$_2$As$_2$, Phys. Rev. B 88, 014526 (2013).
[2] W. Jayasekara, Y. Lee, Abhishek Pandey, et al., Stripe antiferromagnetic spin fluctuations in SrCo$_2$As$_2$, Phys. Rev. Lett. 111, 157001 (2013).
[3] Y. Li, Z. Yin, Z. Liu, et al., Coexistence of Ferromagnetic and Stripe Antiferromagnetic Spin Fluctuations in SrCo$_2$As$_2$, Phys. Rev. Lett. 122, 117204 (2019).
[4] A. Sapkota, B. G. Ueland, V. K. Anand, et al., Effective one-dimensional coupling in the highly frustrated square-lattice itinerant magnet CaCo$_{2-y}$As$_2$, Phys. Rev. Lett. 119, 147201 (2017).
[5] A. Pandey, Y. Liu, Saroj L. Samal, et al., KCo$_2$As$_2$: A new portal for the physics of high-purity metals, Phys. Rev. Mater. 6, 075001 (2022).

Level for award;(Hons, MSc, PhD, N/A)?

MSc