Induced magnetic moment of Eu3+ ions in GaN

Abstract

Magnetic semiconductors with coupled magnetic and electronic properties are of high technological and fundamental importance. Rare-earth elements can be used to introduce magnetic moments associated with the uncompensated spin of 4f-electrons into the semiconductor hosts. The luminescence produced by rare-earth doped semiconductors also attracts considerable interest due to the possibility of electrical excitation of characteristic sharp emission lines from intra 4f-shell transitions. Recently, electroluminescence of Eu-doped GaN in current-injection mode was demonstrated in p-n junction diode structures grown by organometallic vapour phase epitaxy. Unlike most other trivalent rare-earth ions, Eu3+ ions possess no magnetic moment in the ground state. Here we report the detection of an induced magnetic moment of Eu3+ ions in GaN which is associated with the 7F2 final state of 5D0→7F2 optical transitions emitting at 622 nm. The prospect of controlling magnetic moments electrically or optically will lead to the development of novel magneto-optic devices.

Study of Dy-doped Bi2Te3: thin film growth and magnetic properties

“…On the other hand, samples with Dy concentrations of x < 0.055 exhibited magnetic moments that were larger than expected which may be related to additional contributions arising from a spin polarisation of the Bi 2 Te 3 matrix by the Dy atoms. Giant magnetic moments, which exceed free ion values, arising from matrix polarisation of the host material have been reported in some rare earth-doped dilute magnetic semiconductors, such as Eu-doped GaN [65] and Gd-doped GaN [66], where in case of Gd doping effective magnetic moments of 4000 µ B have been reported. Investigations into the local electronic structures of the rare earth dopants in 3D TIs using extended x-ray absorption fine structure (EXAFS) may be useful in revealing the origin of these discrepancies, especially if they are related to differences in electronic configuration.…”

Hydroxyapatite nanocrystals: colloidal chemistry, assembly and their biological applications

“…[48][49][50][51][52][53][54][55][56] For the mixed solvent system of octadecylamine, oleic acid and water, different rareearth ions (La 3+ , Ce 3+ , Nd 3+ , Eu 3+ , Gd 3+ , Tb 3+ , Er 3+ , Tm 3+ , Yb 3+ , etc.) and F − ions are chosen as doping ions.…”

Luminescence and magnetic properties of novel nanoparticle-sheathed 3D Micro-Architectures of Fe0.5R0.5(MoO4)1.5:Ln3+ (R = Gd3+, La3+), (Ln = Eu, Tb, Dy) for bifunctional application

“…The existence of non-magnetic elements Gd 3+ or La 3+ with magnetic iron molybdates should either increase or decrease the net magnetic moment through exchange interaction. Kachkanov et al [17] reported that, although most of the trivalent rare-earth ions exhibit a lack of magnetic moment at room temperature, an induced magnetic moment has been detected in Eu 3+ ions doped with non magnetic GaN. Hughes et al [18] reported that, via an indirect exchange interaction, the localized magnetic moments of the rare earth elements were coupled using chemically inert 4f electrons, resulting in a wide magnetism range.…”