Prediction of Antiferromagnetism in Barium Chromium Phosphide Confirmed after Synthesis

TL;DR

This study combines theoretical predictions and experimental validation to demonstrate that BaCr2P2 is an antiferromagnetic material with a structure similar to iron-pnictide superconductors, showing a transition at around 60 K.

Contribution

The paper predicts antiferromagnetism in BaCr2P2 using DFT and confirms it experimentally after synthesis, establishing its structural and magnetic properties.

Findings

DFT predicts antiferromagnetic order in BaCr2P2.

Experimental synthesis confirms the predicted crystal structure.

Magnetic measurements show a transition at approximately 60 K.

Abstract

We have carried out density-functional theory (DFT) calculations for the chromium pnictide BaCr2P2, which is structurally analogous to BaFe2As2, a parent compound for iron-pnictide superconductors. Evolutionary methods combined with DFT predict that the chromium analog has the same crystal structure as the latter. DFT also predicts Neel antiferromagnetic order on the chromium sites. Comparison with a simple electron-hopping model over a square lattice of chromium atoms suggests that it is due to residual nesting of the Fermi surfaces. We have confirmed the DFT predictions directly after the successful synthesis of polycrystalline samples of BaCr2P2. X-ray diffraction recovers the predicted crystal structure to high accuracy, while magnetic susceptibility and specific-heat measurements are consistent with a transition to an antiferromagnetically ordered state below T_N ~ 60 K.