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Creator | Title | Description | Subject | Date |
1 |
 | Scarpulla, Michael | Carrier concentration dependencies of magnetization & transport in Ga1-xMnxAs1-yTey | We have investigated the transport and magnetization characteristics of Ga1-xMnxAs intentionally compensated with shallow Te donors. Using ion implantation followed by pulsed-laser melting, we vary the Te compensation and drive the system through a metal-insulator transition (MIT). This MIT is assoc... | Gallium arsenide; Ferromagnetic semiconductors; Magnetization; Resistivity | 2005 |
2 |
 | Scarpulla, Michael | Compensation-dependent in-plane magnetization reversal processes in Ga1-xMnxP1-ySy | We report the effect of dilute alloying of the anion sublattice with S on the in-plane uniaxial magnetic anisotropy and magnetization reversal process in Ga1−xMnxP as measured by both ferromagnetic resonance (FMR) spectroscopy and superconducting quantum interference device (SQUID) magnetometry. ... | Ferromagnetic semiconductors; Nonmagnetic compensation | 2008-12 |
3 |
 | Scarpulla, Michael | Compositional tuning of ferromagnetism in Ga1-xMnxP | We report the magnetic and transport properties of Ga1-xMnxP synthesized via ion implantation followed by pulsed laser melting over a range of x, namely 0.018 to 0.042. Like Ga1-xMnxAs, Ga1-xMnxP displays a monotonic increase of the ferromagnetic Curie temperature with x associated with the hole-me... | Gallium arsenide; Ferromagnetic semiconductors | 2006-12 |
4 |
 | Scarpulla, Michael | Ferromagnetic Ga1-xMnxAs produced by ion implantation and pulsed-laser melting | We demonstrate the formation of ferromagnetic Ga1-xMnxAs films by Mn ion implantation into GaAs followed by pulsed-laser melting. Irradiation with a single excimer laser pulse results in the epitaxial regrowth of the implanted layer with Mn substitutional fraction up to 80% and effective Curie tempe... | Gallium arsenide; Ferromagnetic semiconductors; Remanent magnetization | 2003 |
5 |
 | Scarpulla, Michael | Magnetic cluster phases of Mn-interstitial-free (Ga,Mn)As | We report an investigation of magnetic cluster phases of (Ga,Mn)As of varying dosages formed by Mn ion implantation followed by pulsed-laser melting (II-PLM). A systematic study of zero-field-cooled and field-cooled magnetization along several high-symmetry crystallographic directions reveals the ... | Magnetic cluster phases; Gallium Arsenide; Ferromagnetic semiconductors; Interstitials | 2007 |
6 |
 | Scarpulla, Michael | Mn L3,2 x-ray absorption and magnetic circular dichroism in ferromagnetic Ga1-xMnxP | We have measured the x-ray absorption and x-ray magnetic circular dichroism (XMCD) at the Mn L3,2 edges in ferromagnetic Ga1−xMnxP films for 0.018≤x≤0.042. Large XMCD asymmetries at the L3 edge indicate significant spin polarization of the density of states at the Fermi energy. The temperatur... | X-ray absorption; Gallium Arsenide; Ferromagnetic semiconductors | 2006 |
7 |
 | Scarpulla, Michael | Mn L3,2 x-ray absorption spectroscopy and magnetic circular dichroism in ferromagnetic Ga1-xMnxP | We have measured the X-ray absorption (XAS) and X-ray magnetic circular dichroism (XMCD) at the Mn i32 edges in ferromagnetic Ga1-xMrixP films for 0.018<x<0.042. Large XMCD asymmetries at the L3 edge indicate significant spin-polarization of the density of states at the Fermi energy. The spectral s... | X-ray absorption; Ferromagnetic semiconductors; X-ray magnetic circular dichroism (XMCD); Gallium Manganese Phosphide; Gallium arsenide | 2007 |
8 |
 | Scarpulla, Michael | Nonmagnetic compensation in ferromagnetic Ga1-xMnxAs and Ga1-xMnxP synthesized by ion implantation and pulsed-laser melting | The electronic and magnetic effects of intentional compensation with nonmagnetic donors are investigated in the ferromagnetic semiconductors Ga1−xMnxAs and Ga1−xMnxP synthesized using ion implantation and pulsed-laser melting. It is demonstrated that compensation with nonmagnetic donors and MnI ... | Ferromagnetic semiconductors | 2008 |
9 |
 | Scarpulla, Michael | Suppression of hole-mediated ferromagnetism in Ga1-xMnxP by hydrogen | We report the passivation of the Mn acceptors in Ga1−xMnxP upon exposure to a hydrogen plasma. The as-grown films are nonmetallic and ferromagnetic with a Curie temperature of TC=55 K. After hydrogenation the sample resistivity increases by approximately three orders of magnitude at room tempera... | Ferromagnetic semiconductors; Hydrogenation | 2008 |