Electron carrier concentration dependent magnetization in ZnO:Co and ZnO:Mn thin films

2007 ◽  
Vol 1035 ◽  
Author(s):  
Zheng Yang ◽  
Maurizio Biasini ◽  
Leelaprasanna J Mandalapu ◽  
Zheng Zuo ◽  
Ward P Beyermann ◽  
...  
Keyword(s):  
Thin Films ◽  
Carrier Concentration ◽  
Concentration Dependence ◽  
Long Range ◽  
Room Temperature ◽  
Zno Thin Films ◽  
X Ray Diffraction ◽  
Electron Carrier ◽  
X Ray ◽  
Curie Temperatures

AbstractCo and Mn ions were implanted into n-type ZnO thin films with different electron carrier concentrations. X-ray diffraction measurements show that the ZnO:Co and ZnO:Mn thin films are of high crystallinity. From magnetization measurements, ferromagnetism was observed in both n-type ZnO:Co and n-type ZnO:Mn thin films with Curie temperatures well-above room temperature. Furthermore, the electron carrier concentration dependence of the saturated magnetization was measured in both types of thin films, and our results support an electron-mediated mechanism for ferromagnetism in ZnO:Co, as predicted by theory. However, our measurements seem to contradict theory for ZnO:Mn, which only predicts long-range ferromagnetism for p-type mediated material.

scholarly journals Origin of Ultraviolet Luminescence from Bulk ZnO Thin Films Grown by Molecular Beam Epitaxy

2011 ◽  
Vol 1 ◽  
pp. 135-139 ◽  
Author(s):  
M. Asghar ◽  
Khalid Mahmood ◽  
Adnan Ali ◽  
M.A. Hasan ◽  
I. Hussain ◽  
...  
Keyword(s):  
Thin Films ◽  
Raman Spectroscopy ◽  
Molecular Beam Epitaxy ◽  
Room Temperature ◽  
Molecular Beam ◽  
Energy Dispersive ◽  
Zno Thin Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Uv Luminescence

Origin of ultraviolet (UV) luminescence from bulk ZnO has been investigated with the help of photoluminescence (PL) measurements. Thin films of ZnO having 52%, 53% and 54% of Zn-contents were prepared by means of molecular beam epitaxy (MBE). We observed a dominant UV line at 3.28 eV and a visible line centered at 2.5 eV in the PL spectrum performed at room temperature. The intensity of UV line has been found to depend upon the Zn percentage in the ZnO layers. Thereby, we correlate the UV line in our samples with the Zn-interstitials-bound exciton (Zni-X) recombination. The results obtained from, x-ray diffraction, the energy dispersive X-ray spectrum (EDAX) and Raman spectroscopy supported the PL results.

Structural Properties of Sputter-Deposited ZnO Thin Films Depending on the Substrate Materials

2005 ◽  
Vol 475-479 ◽  
pp. 1825-1828
Author(s):  
Ju Hyun Myung ◽  
Nam Ho Kim ◽  
Hyoun Woo Kim
Keyword(s):  
Thin Films ◽  
Thermal Annealing ◽  
Room Temperature ◽  
Zno Thin Films ◽  
Zno Films ◽  
X Ray Diffraction ◽  
Axis Orientation ◽  
X Ray ◽  
Sapphire Substrates ◽  
Sputter Deposited

We have demonstrated the growth of ZnO thin films with c-axis orientation at room temperature on various substrates such as Si(100), SiO2, and sapphire by the r.f. magnetron sputtering method. X-ray diffraction (XRD) and scanning electron microscopy altogether indicated that the larger grain size and the higher crystallinity were attained when the ZnO films were deposited on sapphire substrates, compared to the films on Si or SiO2 substrates. The c-axis lattice constant decreased by thermal annealing for the ZnO films deposited on Si or SiO2 substrates, while increased by the thermal annealing for the ZnO films grown on sapphire substrates.

Structure and Conductivity of Iodine-Doped C60 Thin Films

1994 ◽  
Vol 359 ◽  
Author(s):  
Jun Chen ◽  
Haiyan Zhang ◽  
Baoqiong Chen ◽  
Shaoqi Peng ◽  
Ning Ke ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Room Temperature ◽  
Conductivity Measurements ◽  
X Ray Diffraction ◽  
Temperature Conductivity ◽  
Room Temperature Conductivity ◽  
X Ray ◽  
Thermally Activated ◽  
Order Of Magnitude

ABSTRACTWe report here the results of our study on the properties of iodine-doped C60 thin films by IR and optical absorption, X-ray diffraction, and electrical conductivity measurements. The results show that there is no apparent structural change in the iodine-doped samples at room temperature in comparison with that of the undoped films. However, in the electrical conductivity measurements, an increase of more that one order of magnitude in the room temperature conductivity has been observed in the iodine-doped samples. In addition, while the conductivity of the undoped films shows thermally activated temperature dependence, the conductivity of the iodine-doped films was found to be constant over a fairly wide temperature range (from 20°C to 70°C) exhibiting a metallic feature.

Synthesis of CaWO4:(Eu3+,Tb3+) Thin Films by a Two-Step Method at Room Temperature

2013 ◽  
Vol 710 ◽  
pp. 170-173
Author(s):  
Lian Ping Chen ◽  
Yuan Hong Gao
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Phase Composition ◽  
Room Temperature ◽  
Electrochemical Techniques ◽  
Luminescent Properties ◽  
X Ray Diffraction ◽  
Step Method ◽  
X Ray ◽  
Rare Earth Doped

It is hardly possible to obtain rare earth doped CaWO4thin films directly through electrochemical techniques. A two-step method has been proposed to synthesize CaWO4:(Eu3+,Tb3+) thin films at room temperature. X-ray diffraction, energy dispersive X-ray analysis, spectrophotometer were used to characterize their phase, composition and luminescent properties. Results reveal that (Eu3+,Tb3+)-doped CaWO4films have a tetragonal phase. When the ratio of n (Eu)/n (Tb) in the solution is up to 3:1, CaWO4:(Eu3+,Tb3+) thin film will be enriched with Tb element; on the contrary, when the ratio in the solution is lower than 1:4, CaWO4:(Eu3+,Tb3+) thin film will be enriched with Eu element. Under the excitation of 242 nm, sharp emission peaks at 612, 543, 489 and 589 nm have been observed for CaWO4:(Eu3+,Tb3+) thin films.

Long-term Room Temperature Instability in Thermal Conductivity of InGaZnO Thin Films

MRS Advances ◽  
2016 ◽  
Vol 1 (22) ◽  
pp. 1631-1636 ◽  
Author(s):  
Boya Cui ◽  
D. Bruce Buchholz ◽  
Li Zeng ◽  
Michael Bedzyk ◽  
Robert P. H. Chang ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Room Temperature ◽  
Storage Time ◽  
Laser Deposition ◽  
Low Oxygen ◽  
X Ray Diffraction ◽  
3Ω Method ◽  
X Ray

ABSTRACTThe cross-plane thermal conductivities of InGaZnO (IGZO) thin films in different morphologies were measured on three occasions within 19 months, using the 3ω method at room temperature 300 K. Amorphous (a-), semi-crystalline (semi-c-) and crystalline (c-) IGZO films were grown by pulsed laser deposition (PLD), followed by X-ray diffraction (XRD) for evaluation of film quality and crystallinity. Semi-c-IGZO shows the highest thermal conductivity, even higher than the most ordered crystal-like phase. After being stored in dry low-oxygen environment for months, a drastic decrease of semi-c-IGZO thermal conductivity was observed, while the thermal conductivity slightly reduced in c-IGZO and remained unchanged in a-IGZO. This change in thermal conductivity with storage time can be attributed to film structural relaxation and vacancy diffusion to grain boundaries.

Formation of ZnO Doped with Mn Thin Film by Electrodeposition and Magnetic Behaviour.

2005 ◽  
Vol 879 ◽  
Author(s):  
M. Abid ◽  
C. Terrier ◽  
J-P Ansermet ◽  
K. Hjort
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Room Temperature ◽  
Magnetic Behaviour ◽  
Spectroscopic Methods ◽  
X Ray Diffraction ◽  
X Ray ◽  
Doped Zno ◽  
Mn Doped ◽  
Weak Ferromagnetic

AbstractFollowing the theory, ferromagnetism is predicted in Mn- doped ZnO, Indeed, ferromagnetism above room temperature was recently reported in thin films as well as in bulk samples made of this material. Here, we have prepared Mn doped ZnO by electrodeposition. The samples have been characterized by X-ray diffraction and spectroscopic methods to ensure that the dopants are substitutional. Some samples exhibit weak ferromagnetic properties at room temperature, however to be useful for spintronics this material need additional carriers provided by others means.

scholarly journals Properties of Nanostructure Bismuth Telluride Thin Films Using Thermal Evaporation

2017 ◽  
Vol 2017 ◽  
pp. 1-4 ◽  
Author(s):  
Swati Arora ◽  
Vivek Jaimini ◽  
Subodh Srivastava ◽  
Y. K. Vijay
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Bismuth Telluride ◽  
Room Temperature ◽  
Thermal Evaporation ◽  
Silicon Substrates ◽  
X Ray Diffraction ◽  
Thermal Evaporation Method ◽  
X Ray ◽  
Scanning Electron

Bismuth telluride has high thermoelectric performance at room temperature; in present work, various nanostructure thin films of bismuth telluride were fabricated on silicon substrates at room temperature using thermal evaporation method. Tellurium (Te) and bismuth (Bi) were deposited on silicon substrate in different ratio of thickness. These films were annealed at 50°C and 100°C. After heat treatment, the thin films attained the semiconductor nature. Samples were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM) to show granular growth.

Effect of Flexible Substrates on the Structural and Optical Properties of ZnO Films Deposited by Sputtering Method

2015 ◽  
Vol 1107 ◽  
pp. 678-683 ◽  
Author(s):  
Lam Mui Li ◽  
Azmizam Manie Mani ◽  
Saafie Salleh ◽  
Afishah Alias
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Low Cost ◽  
Argon Plasma ◽  
Optical Transmittance ◽  
Zno Thin Films ◽  
Plastic Substrate ◽  
Zno Films ◽  
X Ray Diffraction ◽  
X Ray

Zinc Oxide (ZnO) has attracted much attention because of its high optical transmittance approximately ~80 % with a wide band gap of (3.3 eV at 300 K) and a relatively low cost material. ZnO thin films were deposited on plastic substrate using RF powered magnetron sputtering method. The target used is ZnO disk with 99.99 % purity. The sputtering processes are carried out with argon gas that flow from 10-15 sccm. Argon is used to sputter the ZnO target because the ability of argon that can remove ZnO layer effectively by sputtering with argon plasma bombardment. The deposited ZnO thin films are characterized using X-Ray Diffraction (XRD) and UV-Vis Spectrometer. The analysis of X-ray diffraction show that good crystalline quality occurs at nominal thickness of 400 nm. The optical studies showed that all the thin films have high average transmittance of approximately 80 % and the estimated value of optical band gap is within 3.1 eV-3.3 eV range.

X-ray diffraction analysis of residual stresses in textured ZnO thin films

2017 ◽  
Vol 395 ◽  
pp. 16-23 ◽  
Author(s):  
E. Dobročka ◽  
P. Novák ◽  
D. Búc ◽  
L. Harmatha ◽  
J. Murín
Keyword(s):  
Thin Films ◽  
Residual Stresses ◽  
Diffraction Analysis ◽  
Zno Thin Films ◽  
X Ray Diffraction ◽  
X Ray
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