\textit{Ab initio} Studies of Magnetism and Topology in solid Pd-rich a-PdSi Alloys

TL;DR

This study computationally investigates the magnetic and topological properties of Pd-rich amorphous Pd-Si alloys, revealing their magnetism and structural features, which could impact future technological applications of bulk metallic glasses.

Contribution

The paper provides the first computational analysis of magnetism and topology in Pd-rich amorphous Pd-Si alloys, identifying their magnetic regions and structural characteristics.

Findings

Amorphous Pd-Si alloys are magnetic for 0 ≤ c < 15 at.% Si.

Pair distribution functions match experimental data.

Magnetization curves confirm net magnetic moments.

Abstract

In 1965 Duwez \textit{et al.} reported having generated an amorphous, stable phase of palladium-silicon in the region 15 to 23 atomic percent (at. \%) silicon. These pioneering efforts have led to the development of solid materials that are now known as Bulk Metallic Glasses (BMG). In 2019 we discovered, computationally, that bulk amorphous Pd becomes magnetic, and so does porous/amorphous Pd. Puzzled by our results we undertook the study of several solid binary systems in the Pd-rich zone; in particular, the study of the glassy metallic alloy $a$-Pd$_{100-c}$Si$_{c}$, for $0 \leq c \leq 22$, ($c$ in at. \%) to see what their topology is, what their electronic properties are and to inquire about their magnetism. Here we show that this metallic glass is in fact magnetic in the region $0 \leq c < 15$. Collaterally we present $\alpha$ and $\beta$ magnetization curves that manifest the net magnetic moment observed. We also discuss the topology and the position of the first few peaks of the pair distribution functions, which agrees well with experiment. The BMGs produced experimentally so far are limited in size, but despite this limitation, recent industrial efforts have developed some useful devices that may revolutionize technology.