Transport and Magnetism in p-type cubic (Ga,Mn)N

Abstract

The electrical and magnetic properties of p-type cubic (Ga,Mn)N thin films grown by plasma-assisted molecular beam epitaxy are reported. Hole concentrations in excess of 1018 cm-3 at room temperature are observed. Activated behaviour is observed down to around 150K, characterised by an acceptor ionisation energy of around 45-60meV. The dependence of hole concentration and ionisation energy on Mn concentration indicates that the shallow acceptor level is not simply due to unintentional co-doping. Thermopower measurements on freestanding films, CV profilometry, and the dependence of conductivity on thickness and growth temperature, all show that the conduction is not due to diffusion into the substrate. We therefore associate the p-type conductivity with the presence of the Mn in the cubic GaN films. Magnetometry measurements indicate a small room temperature ferromagnetic phase, and a significantly larger magnetic coupling at low temperatures.

14 pages

References in corpus (2)

• Electronic structure and magnetism of Mn doped GaN
• P-type conductivity in cubic GaMnN layers grown by molecular beam epitaxy

Cited by in corpus (9)

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• Origin and control of ferromagnetism in dilute magnetic semiconductors and oxides
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• Structural and paramagnetic properties of dilute Ga1-xMnxN
• Electron-electron and electron-phonon correlation effects on the finite temperature electronic and optical properties of zb-GaN
• Magneto-optical spectroscopy of (Ga,Mn)N epilayers
• Impact of substrate temperature on magnetic properties of plasma-assisted molecular beam epitaxy grown (Ga,Mn)N
• Improved-Sensitivity Integral SQUID Magnetometry of (Ga,Mn)N Thin Films in Proximity to Mg-doped GaN