Role of zero-point effects in stabilizing the ground state structure of bulk Fe2P

TL;DR

This paper demonstrates that zero-point effects like vibrations and spin fluctuations are crucial for accurately predicting the ground state structure of Fe2P, revealing quantum stabilization in bulk materials.

Contribution

It shows that including zero-point effects is essential for correct structural predictions of Fe2P, highlighting a rare quantum stabilization in a bulk material.

Findings

Zero-point effects stabilize the experimentally observed structure.

First-principles calculations without zero-point effects favor a different phase.

Potential for magnetic field induced quantum phase transition in Fe2P.

Abstract

Structural stability of Fe2P is investigated in detail using first-principles calculations based on density functional theory. While the orthorhombic C23 phase is found to be energetically more stable, the experiments suggest it to be hexagonal C22 phase. In the present study, we show that in order to obtain the correct ground state structure of Fe2P from the first-principles based methods it is utmost necessary to consider the zero-point effects such as zero-point vibrations and spin fluctuations. This study demonstrates an exceptional case where a bulk material is stabilized by quantum effects, which are usually important in low-dimensional materials. Our results also indicate the possibility of magnetic field induced structural quantum phase transition in Fe2P, which should form the basis for further theoretical and experimental efforts.