Effect of Thickness on Crystal Structure and Magnetic Property of Sr2FeMoO6 Film

2014 ◽  
Vol 894 ◽  
pp. 432-435
Author(s):  
Qin Zhang ◽  
Hui Wang ◽  
Zhen Cui Sun ◽  
Hai Bo Sun
Keyword(s):  
Crystal Structure ◽  
Surface Morphology ◽  
Single Phase ◽  
Annealing Treatment ◽  
Double Perovskite ◽  
Linear Evolution ◽  
Post Annealing ◽  
Electrophoresis Method ◽  
Property Measurement ◽  
Different Thickness

Double perovskite Sr2FeMoO6 film with different thickness was prepared by electrophoresis method on single crystal Si substrate. The post-annealing treatment was carried out at 1100°C with 5% H2/Ar flow. XRD result shows that all the films are of single phase and belong to the I4/m lattice. All the films have no preferred orientation and exhibit typical polycrystal property. Measurement on scanning electron microscope shows that all the three films exhibit similar surface morphology. Different from crystal structure and surface morphology, Curie temperature (TC) shows a non-linear evolution with the thickness of the film. TC of the film increases firstly and then decreases, the highest TC is 300 K. This result indicates that ferromagnetism of the film is strengthened at the thickness about 35μm.

Magnetization Evolution with Hole Doping Level in (Sr2-xNax)FeMoO6

2011 ◽  
Vol 239-242 ◽  
pp. 3165-3168
Author(s):  
Qin Zhang ◽  
Chang Li ◽  
Zhen Feng Xu ◽  
Ke Yan Wang
Keyword(s):  
Crystal Structure ◽  
Saturation Magnetization ◽  
Doping Level ◽  
Single Phase ◽  
Sol Gel ◽  
Double Perovskite ◽  
Hole Doping ◽  
Cation Ordering ◽  
Xrd Pattern ◽  
Method Effects

Hole doped double perovskite compounds (Sr, Na)2FeMoO6 with the Na content of x = 0, 0.02, 0.03, 0.07 and 0.17 have been synthesized by sol-gel method. Effects of hole doping on the crystal structure and magnetic properties of Sr2FeMoO6 have been investigated. XRD pattern indicates that all the samples are of single phase and belong to the space group I4/m. The degree of cation ordering in the Na-doped Sr2FeMoO6 compounds shows a non-monotonic variation with the doping level. The saturation magnetization of the compound increases with x for x<0.17. Similar to the electron doped Sr2FeMoO6, provided that the doped hole enters selectively the spin-down band, the variation of the saturation magnetization can be explained in light of the ferrimagnetic model (FIM).

Effect of Sm Doping on Magnetic Properties of Sr2FeMoO6

2010 ◽  
Vol 663-665 ◽  
pp. 76-79
Author(s):  
Zhen Feng Xu ◽  
Jun Liang ◽  
Juan Pei ◽  
Yan Yan Yin ◽  
Chang Li
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Rare Earth ◽  
Single Phase ◽  
Steric Effect ◽  
Magnetic Measurements ◽  
Double Perovskite ◽  
Rare Earth Ions ◽  
X Ray ◽  
Curie Temperature Tc

New electron doped double perovskite compound (Sr2-xSmx) FeMoO6 (0≤x≤0.25) has been synthesized by solid-state reaction. Crystal structure and magnetic properties of the compounds have been investigated by X-ray powder diffraction (XRD) and magnetic measurements. XRD revealed that all the compounds were of single phase and belonged to a I 4/m lattice. The degree of cationic ordering on the B site was decreased pronouncedly by the electron doping. Different from the results of La- and Nd-doped Sr2FeMoO6, Curie temperature (TC) of (Sr2-xSmx) FeMoO6 decreased first with the doping and then increased beyond x = 0.15, indicating that steric effect was enhanced as the radius of rare-earth ions decreased.

Magnetic Property of Hole-Doped Double Perovskite Compound

2013 ◽  
Vol 464 ◽  
pp. 50-53
Author(s):  
Suo Jia Yuan ◽  
Qin Zhang ◽  
Hai Bo Sun ◽  
Hui Wang
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Doping Level ◽  
Single Phase ◽  
Magnetic Measurements ◽  
Double Perovskite ◽  
Cation Ordering ◽  
High Doping Level ◽  
Xrd Pattern ◽  
X Ray

Crystal structure and magnetic properties of hole-doped double perovskite compounds (Sr, Na)2FeMoO6 have been investigated by means of X-ray powder diffraction (XRD) and magnetic measurements. XRD pattern indicates that all the samples are of single phase and belong to the space group I4/m. The degree of cation ordering in the Na-doped Sr2FeMoO6 compounds shows a non-monotonic variation with the doping level, increasing from x=0 to x=0.03 and decreasing slightly with further increase of the doping. However, the Curie temperature of the compound decreases at low doping level and increases at high doping level.

Magnetization Evolution with the Doping Element in Double Perovskite

2012 ◽  
Vol 490-495 ◽  
pp. 3140-3144
Author(s):  
Qin Zhang ◽  
Qing Wang ◽  
Suo Jia Yuan
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Saturation Magnetization ◽  
Magnetic Moment ◽  
Solid State Reaction ◽  
Single Phase ◽  
Magnetic Moments ◽  
Double Perovskite ◽  
Structure Investigation ◽  
Doping Element

Double perovskite (Sr1.85Ln0.15)FeMoO6 (Ln=Sr, La, Ce, Pr, Nd, Sm and Eu) have been prepared by solid-state reaction. Crystal structure investigation shows that all the samples are of single phase and belong to the I4/m space group. Saturation magnetization of the compounds at 5 K cannot be explained simply by ferrimagnetic model (FIM). However, the saturation magnetization at 100 K of the doped compounds exhibits a linear decrease with the increase of the anti-site defect concentration. Comparison of the saturation magnetization of the compounds at 5 K and 100 K suggests that at 5 K the magnetic moments of Ce, Pr, Nd and Sm align parallel with that of Fe, while the magnetic moment of Eu is anti-parallel with that of Fe.

Structure and Magnetostriction of PrxTb1-xFe1.9Ti0.1 Alloys

2013 ◽  
Vol 281 ◽  
pp. 413-416
Author(s):  
He Yan Liu ◽  
Guo Dong Liu ◽  
Ying Li ◽  
Hong Zhi Luo ◽  
Shao Ling Zhang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Crystal Structure ◽  
Single Phase ◽  
Annealing Treatment ◽  
Annealed Sample ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
Standard Strain ◽  
X Ray ◽  
Type Crystal

The structure and magnetostriction have been investigated for PrxTb1-xFe1.9Ti0.1 alloys by means of the X-ray diffraction phase analysis, vibrating sample magnetometer, and standard strain gauge technique. Comparing the structure of bulk and annealed samples, it can be found that the annealing treatment is of benefit to the formation of single phase with MgCu2-type crystal structure when x0.3. The magnetization at the maximal magnetic field decreases rapidly with increasing Pr content. The magnetostriction for Pr0.2Tb0.8Fe1.9Ti0.1 annealed sample at 900kA/m is 1733ppm. The magnetostriction for PrxTb1-xFe1.9Ti0.1 alloys at 900kA/m also decreases with increasing Pr content.

scholarly journals Thermal Chemically Deposited Zno Nanostructures: Influence of Post-Deposition Annealing Temperature on Ph Sensor Performance

2018 ◽  
Vol 7 (3.11) ◽  
pp. 6
Author(s):  
Aimi Bazilah ◽  
Zaiki Awang ◽  
Shafinaz Sobihana Shariffudin ◽  
Sukreen Hana Herman
Keyword(s):  
Heat Treatment ◽  
Surface Morphology ◽  
Ph Sensor ◽  
Chemical Deposition ◽  
Annealing Treatment ◽  
Zno Nanostructures ◽  
Ph Sensing ◽  
Post Annealing ◽  
Annealing Heat Treatment ◽  
Post Deposition

Zinc oxide (ZnO) nanostructures were synthesized via thermal chemical deposition (TCVD) method and applied as the sensing membrane of an extended-gate field effect transistor (EGFET) pH sensor.  The ZnO nanostructures undergone a post-deposition heat treatment with the temperature ranging from 200-500 °C for 15 min in air ambient. The influence of the post-deposition heat treatment on the physical and pH sensing characteristics was investigated. The FESEM images showed that the surface morphology of the samples were dependent on post-annealing treatment. The as-deposited sample showed the biggest grain size and non-uniformed structures. Applying the post-annealing heat treatment caused the surface morphology to become denser and uniform. The most ideal temperature for the heat treatment for EGFET pH sensor application was found at 300 °C resulting in a pH sensitivity of 48.2 mV/pH with 0.9646 linearity.   

Microstructure and Dielectric Properties of (Ba, Ta) Co-Doped Sr2Nb2O7 Ceramics

2015 ◽  
Vol 815 ◽  
pp. 125-128
Author(s):  
Gang Chen ◽  
Chun Wei Gong ◽  
Chun Lin Fu ◽  
Xiao Dong Peng ◽  
Wei Cai ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Dielectric Constant ◽  
Grain Size ◽  
Dielectric Properties ◽  
Solid State ◽  
Surface Morphology ◽  
Single Phase ◽  
Second Phase ◽  
Maximum Value ◽  
Co Doped

(Sr1-xBax) 2(Nb0.9Ta0.1) 2O7 (SBNT) ceramics were prepared by solid state reaction. The crystal structure of SBNT ceramics, surface morphology and dielectric properties were studied using XRD, SEM and LCR instrument analyzer, respectively. The results show that the grain size decreases with increasing Ba concentration, and all samples show single phase, no second phase can been observed. Addition of Ba ion can improve the dielectric properties of SBN ceramics. The dielectric constant increases first, then decreases; the maximum value (εr=97) can be obtained at x=0.1, the dielectric constant changes slightly with increasing wide frequency.

scholarly journals Effect of Dealloying Time and Post-Annealing on the Surface Morphology and Electrocatalytic Behavior of Nanoporous Copper Films for CO2 Reduction Reaction

2021 ◽  
Author(s):  
Wang-You Zeng ◽  
Jia-Hao Lai ◽  
I-Chung Cheng
Keyword(s):  
Surface Morphology ◽  
Current Density ◽  
Photoelectron Spectroscopy ◽  
Co2 Reduction ◽  
Annealing Treatment ◽  
Reduction Reaction ◽  
Nanoporous Structure ◽  
Post Annealing ◽  
Nanoporous Copper ◽  
Ligament Size

Abstract Electrocatalytic reduction reaction of CO2 (CO2RR) is one of the promising routes to mitigate global warming via transforming greenhouse gas into valuable chemical feedstocks. By adding proper electrocatalysts, such as nanoporous copper (NPC) with an average ligament size of 37 ± 6 nm, hydrocarbons could be produced at a relatively low overpotential. As the dealloying time increased to 156 hrs, the NPC was transformed into CuO nanosheet structure, which yielded larger electrochemical surface area (ECSA) and current density than the as-prepared NPC films. However, the Faraday efficiency (FE) of the major conversion product, formic acid (HCOOH), decreased from 29 to 8% when the nanosheet structure was used as electrocatalyst. On the other hand, the surface morphology of the NPC films remained similar while the average ligament size increased from 37 to 63 nm after a post-annealing treatment at 500 °C for 4 hrs. Both the current density and ECSA of this post-annealed NPC film were nearly 3 times higher than those of as-prepared NPC film, and the FE toward HCOOH increased from 29 to 45%. X-ray photoelectron spectroscopy and Raman spectroscopy revealed that Cu2O were present on the nanoporous structure, which enhanced the selectivity and FE toward HCOOH in CO2RR.

Magnetization and Hole Doping Effects in Double Perovskite Compound Sr2FeMoO6

2014 ◽  
Vol 513-517 ◽  
pp. 223-226
Author(s):  
Qin Zhang
Keyword(s):  
Crystal Structure ◽  
Saturation Magnetization ◽  
Single Phase ◽  
Sol Gel ◽  
Double Perovskite ◽  
Hole Doping ◽  
Cation Ordering ◽  
Xrd Pattern ◽  
Doping Effects ◽  
Method Effects

Hole doped compounds (Sr, Na)2FeMoO6with the Na content of x = 0, 0.02, 0.03, 0.07 and 0.17 have been synthesized by sol-gel method. Effects of hole doping on the crystal structure and magnetic properties of Sr2FeMoO6have been investigated. XRD pattern indicates that all the samples are of single phase and belong to the space groupI4/m. The degree of cation ordering in the Na-doped Sr2FeMoO6compounds shows a non-monotonic variation with the doping level. The saturation magnetization of the compound increases with x for x<0.17. Provided that the doped hole enters selectively the spin-down band, the variation of the saturation magnetization can be explained in light of the ferrimagnetic model (FIM), which is Similar to the electron doped Sr2FeMoO6.

ФОРМИРОВАНИЕ ПЕРЕХОДНОГО СЛОЯ ALN НА ТЕМПЛЕЙТАХ 3С-SIC/SI(111) МЕТОДОМ АММИАЧНОЙ МОЛЕКУЛЯРНО-ЛУЧЕВОЙ ЭПИТАКСИИ

2020 ◽  
Vol 96 (3s) ◽  
pp. 148-153
Author(s):  
С.Д. Федотов ◽  
А.В. Бабаев ◽  
В.Н. Стаценко ◽  
К.А. Царик ◽  
В.К. Неволин
Keyword(s):  
Crystal Structure ◽  
Growth Rate ◽  
Low Temperature ◽  
Surface Morphology ◽  
Single Crystal ◽  
Root Mean Square Roughness ◽  
Rate Variation ◽  
Mean Square ◽  
Nucleation Layer ◽  
Low Temperature Epitaxy

Представлены результаты изучения морфологии поверхности и структуры слоев AlN, сформированных аммиачной МЛЭ на темплейтах 3C-SiC/Si(111) on-axis- и 4° off-axis-разориентации. Опробован технологический режим низкотемпературной эпитаксии зародышевого слоя AlN на поверхности 3C-SiC(111). Среднеквадратичная шероховатость поверхности (5 х 5 мкм) слоев AlN толщиной 150 ± 50 нм составила 2,5-3,5 нм на темплейтах 3C-SiC/Si(111) on-axis и 3,3-3,5 нм на 4° off-axis. Показано уменьшение шероховатости смачивающего слоя AlN при изменении скорости роста. Получены монокристаллические слои AlN(0002) со значениями FWHM (ω-геометрия) 1,4-1,6°. The paper presents the surface morphology and crystal structure of AlN layers formed by ammonia MBE on 3C-SiC/Si(111) on-axis and 4° off-axis disorientation. It offers the technological approach of low-temperature epitaxy of the AlN nucleation layer on the 3C-SiC (111) surface. Root mean square roughness (5 х 5 |xm) of AlN layers with thickness of 150 ± 50 nm was 2,5-3,5 nm onto on-axis templates and 3.3-3.5 nm onto 4° off-axis. It appears that the RMS roughness of the AlN surface is changing with the growth rate variation. Single-crystal AlN(0002) layers with FWHM values (ω-geometry) of 1.4-1.6° have been obtained.

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