Intrinsic Properties of Stoichiometric LaOFeP

TL;DR

This study characterizes the intrinsic physical properties of stoichiometric LaOFeP, revealing it is metallic and non-superconducting above 0.35 K with no magnetic order or structural distortions, and compares it to LaOFeAs.

Contribution

It provides detailed experimental data on LaOFeP's properties and proposes a model explaining differences with LaOFeAs based on tetrahedral geometry.

Findings

LaOFeP is metallic and non-superconducting above 0.35 K.

No structural distortions or magnetic order detected in LaOFeP.

Differences between LaOFeP and LaOFeAs explained by tetrahedral shape.

Abstract

DC and ac magnetization, resistivity, specific heat, and neutron diffraction data reveal that stoichiometric LaOFeP is metallic and non-superconducting above T = 0.35 K, with gamma = 12.5 mJ/mol*K. Neutron diffraction data at room temperature and T = 10 K are well described by the stoichiometric, tetragonal ZrCuSiAs structure and show no signs of structural distortions or long range magnetic ordering, to an estimated detectability limit of 0.07 uB/Fe. We propose a model, based on the shape of the iron-pnictide tetrahedron, that explains the differences between LaOFeP and LaOFeAs, the parent compound of the recently discovered high-Tc oxyarsenides, which, in contrast, shows both structural and spin density wave (SDW) transitions.