Doping-dependent Phase Diagram of LaO{\it M}As ({\it M}=V--Cu) and Electron-type Superconductivity near Ferromagnetic Instability

TL;DR

This study maps the doping-dependent phase diagram of LaO{ extit{M}}As ({ extit{M}}=V--Cu), revealing magnetic phases and electron-type superconductivity near ferromagnetic instability through first-principles calculations.

Contribution

It provides the first comprehensive doping-dependent phase diagram for LaO{ extit{M}}As and analyzes the magnetic and superconducting properties using Fermi surface analysis.

Findings

LaO{ extit{M}}As exhibits antiferromagnetic semiconducting behavior near LaOMnAs.

LaOFeAs and LaONiAs are at the magnetic phase boundary where superconductivity occurs.

Superconductivity in these materials is of electron-type origin, influenced by ferromagnetic spin fluctuations.

Abstract

By first-principles calculations, we present a doping-dependent phase diagram of LaO{\it M}As ({\it M}=V--Cu) family. It is characterized as antiferromagnetic semiconductor around LaOMnAs side and ferromagnetic metal around LaOCoAs. Both LaOFeAs and LaONiAs, where superconductivity were discovered, are located at the borderline of magnetic phases. Extensive Fermi surface analysis suggests that the observed superconductivity is of electron-type in its origin. We discuss possible pairing mechanisms in the context of competing ferromagnetic phases found in this work and the ferromagnetic spin fluctuations.