scholarly journals Linear Tuning of Phase-Matching Temperature in LiNbO3:Zr Crystals by MgO Co-Doping

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4155
Author(s):  
Tengfei Kong ◽  
Hongde Liu ◽  
Liyun Xue ◽  
Weiwei Wang ◽  
Shahzad Saeed ◽  
...  
Keyword(s):  
Room Temperature ◽  
Incident Angle ◽  
Phase Matching ◽  
Defect Structures ◽  
Defect Analysis ◽  
High Quality ◽  
Damage Resistance ◽  
Co Doping ◽  
532 Nm ◽  
Co Doped

We grew a series of co-doped LiNbO3 crystals with fixed 1.5 mol % ZrO2 and various MgO concentrations (1.0, 3.0, 4.0, 6.0 mol %), and investigated their optical properties and defect structures. By 3.0 mol % MgO co-doping, the optical damage resistance at 532 nm reached 6.5 × 106 W/cm2, while the phase-matching temperature for doubling 1064 nm was only 29.3 °C—close to room temperature—which was conducive to realizing the 90° phase matching at room temperature by slightly modulating the incident angle of the fundamental beam. Notably, we found that the phase-matching temperature increased linearly with the increase of MgO doping, and this linear dependence helped us to grow the high-quality crystal for room temperature 90° phase matching. Moreover, the defect analysis indicated that the linear tuning of phase-matching temperature might be attributed to Mg Li + + Zr Nb − neutral pairs in crystals.

STUDY ON THE OPTICAL PROPERTIES OF Mg, In CO-DOPED LITHIUM NIOBATE CRYSTALS

2007 ◽  
Vol 21 (30) ◽  
pp. 2075-2080 ◽  
Author(s):  
ZHAOPENG XU ◽  
BINLIANG JIAO ◽  
YUHENG XU ◽  
SHIWEN XU
Keyword(s):  
Room Temperature ◽  
Second Harmonic ◽  
Czochralski Method ◽  
Phase Matching ◽  
Damage Resistance ◽  
Order Of Magnitude ◽  
Photo Damage ◽  
Lithium Niobate Crystals ◽  
Co Doped ◽  
Mg Doped

Mg : In : LiNbO 3 crystals co-doped with 3 mol% MgO and 0.5 mol%, 1 mol% and 1.5 mol% In 2 O 3 were grown by the Czochralski method. The crystal composition and defect structure were analyzed by the infrared (IR) spectroscopy. The photo-damage resistance ability of the Mg : In : LiNbO 3 crystals was observed by straightly observing the transmission facula distortion method. The second harmonic generation (SHG) property of the Mg : In : LiNbO 3 crystals was measured. The results show that the photo-damage resistance ability of the Mg : In : LiNbO 3 crystals increases over one order of magnitude in comparison with that of the Mg : LiNbO 3 crystal. The phase-matching temperature of the Mg : In : LiNbO 3 crystals is near the room temperature. The SHG conversation efficiency of the Mg : In : LiNbO 3 crystals is higher than that of Mg -doped and In -doped LiNbO 3 crystals.

The Structural, Electrical, Magnetic Properties of (Cu, Co) Co-Doped ZnO Thin Film

2014 ◽  
Vol 556-562 ◽  
pp. 429-432
Author(s):  
Ping Cao ◽  
Yue Bai ◽  
Zhi Qu
Keyword(s):  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Sol Gel ◽  
Hall Effect Measurement ◽  
Ferromagnetic Semiconductors ◽  
Zno Thin Film ◽  
Zno Film ◽  
Co Doping ◽  
Doped Zno ◽  
Co Doped

Successful synthesis of room-temperature ferromagnetic semiconductors, (Cu, Co) co-doped ZnO film is obtained by sol-gel method. It is found that the essential ingredient in achieving room-temperature ferromagnetism is Cu co-doping. By Hall-effect measurement ap-type conductivity was observed for the Cu co-doped films, which induced the room-temperature ferromagnetism.

scholarly journals Defect induced room temperature ferromagnetism in high quality Co-doped ZnO bulk samples

2020 ◽  
pp. 157772
Author(s):  
M.P.F. de Godoy ◽  
X. Gratens ◽  
V.A. Chitta ◽  
A. Mesquita ◽  
M.M. de Lima ◽  
...  
Keyword(s):  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
High Quality ◽  
Doped Zno ◽  
Co Doped

scholarly journals Photorefractive Properties of Molybdenum and Hafnium Co-Doped LiNbO3 Crystals

Crystals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 322 ◽  
Author(s):  
Ling Zhu ◽  
Dahuai Zheng ◽  
Shahzad Saeed ◽  
Shuolin Wang ◽  
Hongde Liu ◽  
...  
Keyword(s):  
Response Time ◽  
Absorption Spectra ◽  
High Intensity ◽  
Threshold Concentration ◽  
Czochralski Technique ◽  
Damage Resistance ◽  
Optical Damage ◽  
Uv Visible ◽  
532 Nm ◽  
Co Doped

A series of LiNbO3: Mo, Hf crystals with 0.5 mol % fixed MoO3 and various HfO2 concentrations (0.0, 2.0, and 3.5 mol %) were grown by the Czochralski technique. The photorefractive properties of the LiNbO3: Mo, Hf crystals were investigated by two-wave coupling measurements and the beam distortion method was employed to obtain the optical damage resistance ability. The UV-visible and OH− absorption spectra were also studied. The experimental results imply that the photorefractive properties of LiNbO3: Mo crystals at laser wavelengths of 532, 488, and 442 nm can be greatly enhanced by doping HfO2 over the threshold concentration. At 442 nm especially, the response time of LN: Mo, Hf3.5 can be shortened to 0.9 s with a diffraction efficiency of 46.07% and a photorefractive sensitivity reaching 6.28 cm/J. Besides this, the optical damage resistance at 532 nm is 3 orders of magnitude higher than that of the mono-doped LiNbO3: Mo crystal, which is beneficial for applying it in the field of high-intensity lasers.

Ga1-xGdxN-Based Spin Polarized Light Emitting Diode

2011 ◽  
Vol 1290 ◽  
Author(s):  
Muhammad Jamil ◽  
Tahir Zaidi ◽  
Andrew Melton ◽  
Tianming Xu ◽  
Ian T. Ferguson
Keyword(s):  
Room Temperature ◽  
Light Emitting Diode ◽  
Room Temperature Ferromagnetism ◽  
Polarized Light ◽  
Type Material ◽  
Degree Of Polarization ◽  
Co Doping ◽  
Spin Polarized ◽  
P Type ◽  
Co Doped

ABSTRACTIn this work, a room temperature spin-polarized LED based on ferromagnetic Ga1-xGdxN is reported. The device was grown by metalorganic chemical vapor deposition (MOCVD) and is the first report of a spin-LED based on Ga1-xGdxN. Electroluminescence from this device had a degree of polarization of 14.6% at 5000 Gauss and retained a degree of polarization of 9.3% after removal of the applied magnetic field. Ga1-xGdxN thin films were grown on 2 μm GaN templates and were co-doped with Si and Mg to achieve n-type and p-type materials. Co-doping of the Ga1-xGdxN films with Si produced conductive n-type material, while co-doping with Mg produced compensated p-type material. Both Si and Mg co-doped films exhibited room temperature ferromagnetism, measured by vibrating sample magnetometry.

scholarly journals Increased room temperature ferromagnetism in Co-doped tetrahedral perovskite niobates

2021 ◽  
Vol 8 (10) ◽  
Author(s):  
Yi Zhou ◽  
Qing He ◽  
Fei Zhou ◽  
Xingqi Liao ◽  
Yong Liu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Magnetic Semiconductors ◽  
Room Temperature Ferromagnetism ◽  
Dilute Magnetic Semiconductors ◽  
Defect Band ◽  
Co Doping ◽  
Band Absorption ◽  
Local Spin Polarization ◽  
Curie Temperatures ◽  
Co Doped

Dilute magnetic semiconductors (DMSs), such as (In, Mn)As and (Ga, Mn)As prototypes, are limited to III–V semiconductors with Curie temperatures ( T c ) far from room temperature, thereby hindering their wide application. Here, one kind of DMS based on perovskite niobates is reported. BaM x Nb (1− x ) O 3− δ ( M = Fe, Co) powders are prepared by the composite-hydroxide-mediated method. The addition of M elements endows BaM x Nb (1− x ) O 3− δ with local ferromagnetism. The tetragonal BaCo x Nb (1− x ) O 3− δ nanocrystals can be obtained by Co doping, which shows strong saturation magnetization ( M sat ) of 2.22 emu g −1 , a remnant magnetization ( M r ) of 0.084 emu g −1 and a small coercive field ( H c ) of 167.02 Oe at room temperature. The ab initio calculations indicate that Co doping could lead to a 64% local spin polarization at the Fermi level ( E F ) with net spin DOS of 0.89 electrons eV −1 , this result shows the possibility of maintaining strong ferromagnetism at room temperature. In addition, the trade-off effect between the defect band absorption and ferromagnetic properties of BaM x Nb (1− x ) O 3− δ is verified experimentally and theoretically.

scholarly journals Room temperature 90° phase-matching in zirconium and magnesium co-doped lithium niobate crystals

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Tengfei Kong ◽  
Hongde Liu ◽  
Xinyu Ge ◽  
Da Qu ◽  
Shiguo Liu ◽  
...  
Keyword(s):  
Lithium Niobate ◽  
Room Temperature ◽  
Phase Matching ◽  
Lithium Niobate Crystals ◽  
Co Doped

scholarly journals Enhancement of Resistance Switching in Electrodeposited Co-ZnO Films

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Dewei Chu ◽  
Adnan Younis ◽  
Sean Li
Keyword(s):  
Surface Morphology ◽  
Lattice Structure ◽  
Resistance Switching ◽  
Zno Films ◽  
Dopant Distribution ◽  
High Quality ◽  
Co Doping ◽  
Doped Zno ◽  
Deposited Films ◽  
Co Doped

High quality Co-doped ZnO films were prepared with electrodeposition. The correlation among the surface morphology, lattice structure, Co-dopant distribution, and resistance switching properties of the as-deposited films were investigated. It is found that resistance switching behaviour could be manipulated by controlling the composition of Co in the ZnO films. The significant enhancement of resistance switching was achieved with 5 at% Co doping in the films, and the possible switching mechanism was also discussed.

EFFECT OF HfO2-CODOPING CONCENTRATION ON THE OPTICAL PROPERTIES OF Er3+-DOPED LiNbO3

2010 ◽  
Vol 24 (04n05) ◽  
pp. 495-502 ◽  
Author(s):  
LI DAI ◽  
YAN-QING SU ◽  
SHI-PING WU ◽  
YANG MU ◽  
JING-JIE GUO ◽  
...  
Keyword(s):  
Infrared Absorption Spectrum ◽  
Czochralski Technique ◽  
Visible Absorption ◽  
Damage Resistance ◽  
Transmitted Beam ◽  
Structure Defects ◽  
Optical Damage ◽  
X Ray ◽  
Co Doping ◽  
Co Doped

A series of Hf , Er co-doped LiNbO 3 crystals were grown by Czochralski technique with 1 mol% of Er 2 O 3 and with 2, 4, 6 and 8 mol% of HfO 2, respectively. The optical damage resistance of Hf : Er : LiNbO 3 crystals was studied by the transmitted beam pattern distortion method. The optical damage resistance of Hf (6 mol%): Er : LiNbO 3 crystals is about two orders of magnitude higher than that in Hf : Er : LiNbO 3. The X-ray power diffraction, the ultraviolet-visible absorption spectra and the infrared absorption spectrum were measured and discussed in terms of the spectrometric characterization and the defect structure of crystals. The results showed that with mild co-doping with HfO 2, Er 3+ substitutes Nb 5+, whereas with heavy co-doping, a part of Er 3+ substitutes Li +. The structure defects were discussed in this paper to explain the improvement of the optical damage resistance in the Hf : Er : LiNbO 3.

P- and n-Type Doping in SiC Sublimation Epitaxy Using Highly Doped Substrates

2009 ◽  
Vol 615-617 ◽  
pp. 85-88 ◽  
Author(s):  
Philip Hens ◽  
Mikael Syväjärvi ◽  
Felix Oehlschläger ◽  
Peter J. Wellmann ◽  
Rositza Yakimova
Keyword(s):  
Growth Process ◽  
Room Temperature ◽  
Co Doping ◽  
P Type ◽  
Substrate Doping ◽  
Co Doped

The co-doping of nitrogen and aluminum has been studied in the sublimation epitaxy growth process. It is shown that the doping may be tuned from n-type to p-type by effect of substrate doping, growth face and volume of the growth crucible. The co-doped layers show a nearly ideal I V characteristic and luminescence at room temperature.

Sign in / Sign up

Export Citation Format

Share Document