Excitation and De-Excitation Mechanisms of Rare-Earth Ions in III-V Compounds: Optically Detected Microwave-Induced Impact Ionization of Yb Dopant in Inp

1993 ◽  
Vol 301 ◽  
Author(s):  
T. Gregorkiewicz ◽  
B.J. Heijmink Liesertr ◽  
I. Tsimperidis ◽  
I. de Maat-Gersdorf ◽  
C.A.J. Ammerlaan ◽  
...  
Keyword(s):  
Rare Earth ◽  
Direct Evidence ◽  
Impact Ionization ◽  
Rare Earth Ions ◽  
Nonradiative Recombination ◽  
Excitation Mechanisms ◽  
Optically Detected ◽  
Recombination Channel ◽  
Experimental Findings ◽  
First Time

ABSTRACTThe excitation mechanisms of rare-earth dopants in III-V semiconductors are being reviewed. The discussion is focused on ytterbium-doped InP crystals for which a particularly large amount of experimental data has been gathered. Here, the results obtained recently by optically detected microwave-induced impact ionization are being examined in detail. On the basis of the experimental findings it is argued that the intrashell luminescence is excited by an intermediate state involving binding of an exciton. Direct evidence for the existence of such a state, of pseudoacceptor type, will be given. The nonradiative recombination channel responsible for the fast decay of Yb luminescence will also be discussed and, for the first time, evidence for an Auger process will be presented. It will also be shown that the nonradiative channel may be effectively blocked by impact ionization of a participating carrier.

Optically Detected Magnetic Resonance of a Hydrogen-Related Complex Defect in Silicon

1989 ◽  
Vol 163 ◽  
Author(s):  
W.M. Chen ◽  
O.O. Awadelkarim ◽  
B. Monemar ◽  
J.L. Lindström ◽  
G.S. Oehrlein
Keyword(s):  
Magnetic Resonance ◽  
Boron Doped ◽  
Optically Detected Magnetic Resonance ◽  
Temperature Electron ◽  
Related Defect ◽  
Spin Triplet ◽  
Optically Detected ◽  
Recombination Channel ◽  
First Time

AbstractWe present for the first time an optically detected magnetic resonance (ODMR) study of a hydrogen-related defect in silicon. The defect is present in hydrogenated boron-doped silicon single crystals, after room-temperature electron-irradiation. A spin-triplet (S=1) is shown to be the electronic state responsible for the observed ODMR spectrum. An angular dependence study of the ODMR spectrum reveals a C2v defect symmetry. The defect model is discussed in terms of a di-hydrogen-vacancy complex. The role of this defect as an efficient recombination channel (presumably non-radiative) for the non-equilibrium free carriers is also demonstrated.

Direct Evidence for Energy Transfer Between Rare Earth Ions in Terbium-Europium Tungstates

1963 ◽  
Vol 11 (10) ◽  
pp. 458-460 ◽  
Author(s):  
W. W. Holloway ◽  
M. Kestigian ◽  
R. Newman
Keyword(s):  
Energy Transfer ◽  
Rare Earth ◽  
Direct Evidence ◽  
Rare Earth Ions

Carboxyl-functionalized ionic liquids: synthesis, characterization and synergy with rare-earth ions

2018 ◽  
Vol 6 (23) ◽  
pp. 6270-6279 ◽  
Author(s):  
Talita Jordanna de Souza Ramos ◽  
Guilherme Henrique Berton ◽  
Tania Maria Cassol ◽  
Severino Alves Júnior
Keyword(s):  
Ionic Liquids ◽  
Rare Earth ◽  
Carboxylic Acids ◽  
Room Temperature ◽  
Rare Earth Ions ◽  
Room Temperature Ionic Liquids ◽  
First Time

Herein, we describe for the first time room temperature ionic liquids (RTILs) and imidazole-based cations with appended carboxylic acids as terminals, which are directly derived from the anhydrides.

Doubly TEMPO-coordinated gadolinium(iii), lanthanum(iii), and yttrium(iii) complexes. Strong superexchange coupling across rare earth ions

2014 ◽  
Vol 43 (15) ◽  
pp. 5893-5898 ◽  
Author(s):  
Rina Murakami ◽  
Takeshi Nakamura ◽  
Takayuki Ishida
Keyword(s):  
Crystal Structure ◽  
Rare Earth ◽  
Rare Earth Ions ◽  
Magnetic Study ◽  
X Ray ◽  
Superexchange Coupling ◽  
First Time

The X-ray crystal structure of TEMPO-coordinated lanthanide compounds was determined for the first time. The magnetic study clarified that [Gd(hfac)3(TEMPO)2] behaved as a ground Stotal = 7/2 species. The La and Y analogues showed the superexchange interactions across the diamagnetic ions.

X-ray Excited Optical Luminescence Studies of InGaN and Rare-Earth Doped GaN Epilayers

2004 ◽  
Vol 831 ◽  
Author(s):  
V. Katchkanov ◽  
J.F.W. Mosselmans ◽  
K.P. O'Donnell ◽  
N.R.J. Poolton ◽  
S. Hernandez
Keyword(s):  
Rare Earth ◽  
Yellow Emission ◽  
Core Excitation ◽  
Yellow Band ◽  
X Ray ◽  
Optical Luminescence ◽  
Optically Detected ◽  
First Time ◽  
X Ray Absorption ◽  
Rare Earth Doped

ABSTRACTA successful attempt to use X-ray Excited Optical Luminescence (XEOL) for the detection of Extended X-ray Absorption Fine Structure (EXAFS) in III-nitrides is reported. The samples studied were InGaN and rare-earth (RE) doped GaN epilayers. For the first time Ga K-edge EXAFS oscillations were measured by monitoring the well-known “yellow” emission of GaN at 560 nm. The analysis of Optically Detected (OD) EXAFS data confirmed the expected local structure for Ga in GaN. The intensity oscillation of the “yellow” band when X-ray energy was scanned across the Ga K-edge indicates that core excitation of Ga atom has a high probability of transfer to defects responsible for “yellow” emission.

Excitation mechanisms and optical properties of rare-earth ions in semiconductors

1991 ◽  
Vol 66 (21) ◽  
pp. 2782-2785 ◽  
Author(s):  
Stefan Schmitt-Rink ◽  
Chandra M. Varma ◽  
Anthony F. J. Levi
Keyword(s):  
Optical Properties ◽  
Rare Earth ◽  
Rare Earth Ions ◽  
Excitation Mechanisms

Characterization of Rare-Earth Fluoride Anti-Stokes Phosphors by Scanning arid Transmission Electron Microscopy

1971 ◽  
Vol 29 ◽  
pp. 142-143
Author(s):  
N. M. P. Low ◽  
L. E. Brosselard
Keyword(s):  
Electron Microscopy ◽  
Rare Earth ◽  
Elevated Temperatures ◽  
Stoichiometric Composition ◽  
Rare Earth Ions ◽  
Crystalline Solid ◽  
Precipitation Process ◽  
Rare Earth Fluoride ◽  
Earth Fluoride ◽  
Rare Earth Fluorides

There has been considerable interest over the past several years in materials capable of converting infrared radiation to visible light by means of sequential excitation in two or more steps. Several rare-earth trifluorides (LaF3, YF3, GdF3, and LuF3) containing a small amount of other trivalent rare-earth ions (Yb3+ and Er3+, or Ho3+, or Tm3+) have been found to exhibit such phenomenon. The methods of preparation of these rare-earth fluorides in the crystalline solid form generally involve a co-precipitation process and a subsequent solid state reaction at elevated temperatures. This investigation was undertaken to examine the morphological features of both the precipitated and the thermally treated fluoride powders by both transmission and scanning electron microscopy.Rare-earth oxides of stoichiometric composition were dissolved in nitric acid and the mixed rare-earth fluoride was then coprecipitated out as fine granules by the addition of excess hydrofluoric acid. The precipitated rare-earth fluorides were washed with water, separated from the aqueous solution, and oven-dried.

Structural, Morphological and Magnetic Characterization of Sm-substituted Ni-Zn Ferrite

2020 ◽  
Vol 10 (2) ◽  
pp. 152-156 ◽  
Author(s):  
Muhammad Hanif bin Zahari ◽  
Beh Hoe Guan ◽  
Lee Kean Chuan ◽  
Afiq Azri bin Zainudin
Keyword(s):  
Magnetic Properties ◽  
Rare Earth ◽  
Saturation Magnetization ◽  
Sol Gel ◽  
Magnetic Behavior ◽  
Rare Earth Ions ◽  
Ion Concentration ◽  
Zn Ferrite ◽  
Auto Combustion ◽  
Combustion Technique

Background: Rare earth materials are known for its salient electrical insulation properties with high values of electrical resistivity. It is expected that the substitution of rare earth ions into spinel ferrites could significantly alter its magnetic properties. In this work, the effect of the addition of Samarium ions on the structural, morphological and magnetic properties of Ni0.5Zn0.5SmxFe2-xO4 (x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) synthesized using sol-gel auto combustion technique was investigated. Methods: A series of Samarium-substituted Ni-Zn ferrite nanoparticles (Ni0.5Zn0.5SmxFe2-xO4 where x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) were synthesized by sol-gel auto-combustion technique. Structural, morphological and magnetic properties of the samples were examined through X-Ray Diffraction (XRD), Field-Emission Scanning Electron Microscope (FESEM) and Vibrating Sample Magnetometer (VSM) measurements. Results: XRD patterns revealed single-phased samples with spinel cubic structure up to x= 0.04. The average crystallite size of the samples varied in the range of 41.8 – 85.6 nm. The prepared samples exhibited agglomerated particles with larger grain size observed in Sm-substituted Ni-Zn ferrite as compared to the unsubstituted sample. The prepared samples exhibited typical soft magnetic behavior as evidenced by the small coercivity field. The magnetic saturation, Ms values decreased as the Sm3+ concentration increases. Conclusion: The substituted Ni-Zn ferrites form agglomerated particles inching towards more uniform microstructure with each increase in Sm3+ substitution. The saturation magnetization of substituted samples decreases with the increase of samarium ion concentration. The decrease in saturation magnetization can be explained based on weak super exchange interaction between A and B sites. The difference in magnetic properties between the samples despite the slight difference in Sm3+ concentrations suggests that the properties of the NiZnFe2O4 can be ‘tuned’, depending on the present need, through the substitution of Fe3+ with rare earth ions.

Sign in / Sign up

Export Citation Format

Share Document