Evidence for Mn2+ fine structure in CdMnSe/ZnSe quantum dots caused by their low dimensionality

JETP Letters - The axial fine structure with strong positive zero-field splitting for Mn2+ ions in CdMnSe/ZnSe quantum dots caused by their low dimensionality was revealed. Magnetic resonance was...     

Application of High-Frequency Electron Paramagnetic Resonance/Electron Spin Echo for the Identification of the Impurity Composition and Electronic Structure of Ceramics Based Garnets

Physics of the Solid State - Electron paramagnetic resonance (EPR) spectra of Ce3+, Yb3+, Cr3+, and Gd3+ impurity ions in yttrium aluminum garnet Y3Al5O12 (YAG) ceramics were detected and...     

Physical Foundations of an Application of Scanning Probe with Spin Centers in SiC for the Submicron Quantum Probing of Magnetic Fields and Temperatures

Optical and radio-frequency physical effects that allow spin manipulations at room temperature using magnetic resonance, effects of anticrossing levels in the ground and excited quadruplet spin states, and cross-relaxation resonances in ensembles of spin color centers in silicon carbide micro- and nanocrystals have been demonstrated. A scanning device where ensembles of spin centers placed on the tip of the cantilever probe of an atomic force microscope serve as sensors of magnetic and temperature fields with a submicron spatial resolution has been considered.     

High-Temperature Spin Manipulation on Color Centers in Rhombic Silicon Carbide Polytype 21R-SiC

JETP Letters - A family of atomic-scale color centers, the spin state of which can be controlled via optical and microwave channels, has been found in the rhombic polytype of silicon carbide...     

Manifestations of Electron–Nuclear Interactions in the High-Frequency ENDOR/ODMR Spectra for Triplet Si–C Divacancies in 13C-Enriched SiC

JETP Letters - The frequencies of electron–nuclear interactions with 13C and 29Si nuclei on remote coordination spheres are determined in triplet spin centers in the form of neutral...     

Properties of erbium luminescence in bulk crystals of silicon carbide

The infrared luminescence of Er³⁺ ions has been studied in bulk crystals of silicon carbide 6H-SiC doped with erbium in the process of their growth. The erbium centers of different symmetry in the crystals are revealed by the EPR technique. A number of intense luminescence bands of erbium ions are observed at a wavelength of about 1.54 μm. The luminescence can be excited by the light with quantum energies above and below the band gap of SiC. It is found that the luminescence exhibits unusual temperature behavior: as the temperature increases, the luminescence intensity abruptly rises starting with 77 K, passes through a maximum at ∼240 K, and, in the vicinity of ∼400 K, decreases down to the values observed at 77 K. The activation energies for the flare-up and quenching of the Er³⁺ luminescence are estimated at E _A ≈130 and ≈350 meV, respectively. The mechanisms of the flare-up and quenching of the Er³⁺ luminescence in SiC are discussed. __________ Translated from Fizika Tverdogo Tela, Vol. 42, No. 5, 2000, pp. 809–815. Original Russian Text Copyright ? 2000 by Babunts, Vetrov, Il’in, Mokhov, Romanov, Khramtsov, Baranov.     

Influence of Antisite Defects in Yttrium–Aluminum Garnet on Paramagnetic Centers of Ce3+ and Tb3+

Physics of the Solid State - In yttrium aluminum garnet (YAG) crystals containing terbium and cerium impurities, along with the main EPR signals of Tb3+ and Се3+ ions located in the...     

Features of High-Frequency EPR/ESE/ODMR Spectroscopy of NV-Defects in Diamond

Physics of the Solid State - The methods of high-frequency electron paramagnetic resonance (EPR), electron spin echo (ESE) and optically detected magnetic resonance (ODMR) are used to study the...     

Electron paramagnetic resonance of Er<Superscript>3+</Superscript> ions in a polycrystalline α-Al<Subscript>2</Subscript>O<Subscript>3</Subscript>

The EPR spectra of rare-earth Er³⁺ ions in a polycrystalline corundum α-Al₂O₃ synthesized by the sol-gel technology were revealed. It is shown that the EPR spectra belong to the Er³⁺ ions in the ground state corresponding to the lower Stark sublevel of the ⁴ I _15/2 term and can be described by the spin Hamiltonian of axial symmetry with an effective spin S = 1/2 and the g tensor with components g _‖ = 12.176 and g _⊥ = 4.14. The average value of the g tensor (〈g〉 = 6.82) corresponds to the Γ₇ state in a cubic field. Erbium is assumed to substitute for aluminum in the Al₂O₃ corundum crystal. The local symmetry C ₃ of the Al³⁺ ion remains despite the pronounced expansion of the lattice around the Er³⁺ ion.     

Temperature-scanned magnetic resonance and the evidence of two-way transfer of a nitrogen nuclear spin hyperfine interaction in coupled NV-N pairs in diamond

New method for the detection of magnetic resonance signals versus temperature is developed on the basis of the temperature dependence of the spin Hamiltonian parameters of the paramagnetic system under investigation. The implementation of this technique is demonstrated on the nitrogen-vacancy (NV) centers in diamonds. Single NV defects and their ensembles are suggested to be almost inertialess temperature sensors. The hyperfine structure of the ¹⁴N nitrogen nuclei of the nitrogen-vacancy center appears to be resolved in the hyperfine structure characteristic of the hyperfine interaction between NV and an N _s center (substitutional nitrogen impurity) in the optically detected magnetic resonance spectra of the molecular NV-N _s complex. Thus, we show that a direct evidence of the two-way transfer of a nitrogen nuclear spin hyperfine interaction in coupled NV-N _s pairs was observed. It is shown that more than 3-fold enhancement of the NV optically detected magnetic resonance signal can be achieved by using water as a collection optics medium.