Effect of Sintering on Structural and Transport Properties on Nanosized Pr0.85Na0.15MnO3

2015 ◽  
Vol 1107 ◽  
pp. 272-277 ◽  
Author(s):  
Siau Wei Ng ◽  
Kean Pah Lim ◽  
S.A. Halim ◽  
Hassan Jumiah ◽  
Albert H.M. Gan ◽  
...  
Keyword(s):  
Grain Size ◽  
Transport Properties ◽  
Electrical Transport ◽  
Boundary Effect ◽  
Sol Gel ◽  
Magnetic Layer ◽  
Electrical Transport Properties ◽  
Orthorhombic Crystal ◽  
Orthorhombic Crystal Structure ◽  
Semiconductor Behavior

We have investigated the structural, microstructure and electrical transport properties of nanosized Pr0.85Na0.15MnO3 (PNMO) synthesized by sol-gel technique and sinter from 600°C to 1000°C. The grain size increases from 67 nm (S600) up to 284 nm (S1000) due to the grain growth during heat treatment. XRD showed that single phase orthorhombic crystal structure of PNMO is fully forms started at 600°C. The resistivity decreased with the increased of grain size and crystallite size due to the reduction of grain boundary effect (dead magnetic layer) which improved their grain conductivity.All samples showed semiconductor behavior where their metal insulator transition temperatures (TMIT) were estimated to be lower than 80K.

Grain boundary effect on the β-boron electrical transport properties at high pressure

2010 ◽  
Vol 97 (17) ◽  
pp. 174101 ◽  
Author(s):  
Ming Li ◽  
Jie Yang ◽  
Karim Snoussi ◽  
Lixin Li ◽  
Huixin Wang ◽  
...  
Keyword(s):  
High Pressure ◽  
Grain Boundary ◽  
Transport Properties ◽  
Electrical Transport ◽  
Boundary Effect ◽  
Electrical Transport Properties ◽  
Grain Boundary Effect

Magnetic and electrical transport properties of Sr2Ti1−xCoxO4 ceramics by sol–gel

2017 ◽  
Vol 31 (17) ◽  
pp. 1750195
Author(s):  
Li Zhang ◽  
Yibao Li ◽  
Zhen Tang ◽  
Yan Deng ◽  
Hui Yuan ◽  
...  
Keyword(s):  
Transport Properties ◽  
Electrical Transport ◽  
Low Temperatures ◽  
Sol Gel ◽  
Variable Range Hopping ◽  
Electrical Transport Properties ◽  
Co Doping ◽  
Hopping Model ◽  
Variable Range Hopping Model ◽  
Co Doped

Microstructures, electrical transport and magnetic properties of Sr[Formula: see text]Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] ceramics are investigated. With Co doping, the Sr[Formula: see text]Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] ceramics remain tetragonal structure while the grain size is decreased with doping. Magnetic moment is enhanced with Co doping and ferromagnetism is observed at low temperatures for Co-doped Sr[Formula: see text]TiO[Formula: see text]. The Sr[Formula: see text]Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] and Sr[Formula: see text]Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] show semiconductor-like transport properties, which can be well fitted by Mott variable range hopping model. The results will provide an effective route to synthesize Sr[Formula: see text]Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] ceramics as well as to investigate the physical properties.

Oxygen Diffusivity and Defect Transport in Pure and Yb Doped Nano-crystalline Ceria

2003 ◽  
Vol 788 ◽  
Author(s):  
Laxmikant Saraf ◽  
V. Shutthanandan ◽  
S. Thevuthasan ◽  
C. M. Wang ◽  
K. T. Koch ◽  
...  
Keyword(s):  
Grain Size ◽  
Electrical Transport ◽  
Oxygen Diffusion ◽  
Defect Density ◽  
Sol Gel ◽  
Ionic Transport ◽  
Nuclear Reaction Analysis ◽  
Electrical Transport Properties ◽  
Nano Crystalline ◽  
Average Grain Size

ABSTRACTOxygen (18O) diffusivity in sol-gel synthesized nano-crystalline ceria films of average grain size of 3 nm and 7 nm, annealed at 300 °C and 450 °C for one hour respectively is examined by nuclear reaction analysis (NRA). Diffusivity and electrical transport properties measured by a. c. impedance spectroscopy were compared with microcrystalline ceria film of average grain size 38 nm annealed at 900 °C for one hour. Effect of enhanced oxygen diffusion along with reduced ionic transport in nano-crystalline ceria and reduced oxygen diffusion along with enhanced ionic transport in microcrystalline ceria are correlated to long range ordering, grain boundary scattering and defect density. Enhancement in the conductivity with reduction in activation energy from 1 eV to 0.5 eV in the case 4 atom% ytterbium (Yb) doped ceria compared to pure ceria is a result of increased oxygen vacancies taking part in the defect transport.

Transport Properties in All Oxide Magnetic Multilayers

2008 ◽  
Vol 587-588 ◽  
pp. 318-322
Author(s):  
H. Sobreiro ◽  
B. Berini ◽  
N. Keller ◽  
David S. Schmool
Keyword(s):  
Transport Properties ◽  
Electrical Transport ◽  
Molecular Beam ◽  
Magnetic Layer ◽  
Magnetic Multilayers ◽  
Magnetic Multilayer ◽  
Electrical Transport Properties ◽  
Appreciable Increase ◽  
Magnetic Layers ◽  
Laser Mbe

The all oxide magnetic multilayer system [LaNiO3/SmFeO3]n (for n = 1 and 2), grown on single crystal SrTiO3(100) substrates, has been produced using the laser MBE (Molecular Beam Epitaxy) technique. We have made a systematic study of the electrical transport properties in the temperature range from 15–300K. As part of this work, we have made a detailed study of the metallic properties of the LaNiO3 layer as a function of the oxygen partial pressure (pO2) and substrate temperature (TS). We have measured magnetic layers of SmFeO3 with LaNiO3 electrodes as a function of the magnetic layer thickness (10 – 470 nm). A non-metallic behaviour is observed with evidence of a “hopping” mechanism at low temperatures. For the n = 2 multilayers, we have measured the temperature dependence of resistance for the sample series with varying LaNiO3 interlayer thickness (t = 2 – 30 nm). We observe an appreciable increase of the low temperature resistance for the interlayer thicknesses between 3.75 – 7.5 nm. This could indicate a change in coupling from ferromagnetic to antiferromagnetic between the magnetic layers.

scholarly journals Magnetic and Electrical Transport Properties of Double Perovskite Sr2FeMoO6Prepared by Sol-Gel Method

2011 ◽  
Vol 8 (s1) ◽  
pp. S189-S194 ◽  
Author(s):  
Yong-Qing Zhai ◽  
Jing Qiao ◽  
Zhang Zhang
Keyword(s):  
Transport Properties ◽  
Electrical Transport ◽  
Room Temperature ◽  
Sol Gel ◽  
Double Perovskite ◽  
Reducing Agent ◽  
Perovskite Oxide ◽  
Electrical Transport Properties ◽  
Gel Method ◽  
Sol Gel Method

With activated carbon for reducing agent, the sol-gel method was used to prepare the giant magnetoresistance materials Sr2FeMoO6, which is the double Perovskite oxide. The structure, morphology, magnetic and electrical transport properties were investigated respectively by x-ray diffraction, scanning electron microscopy and vibrating sample magnetometer. The as-synthesized sample is Sr2FeMoO6with tetragonal crystal structure and I4/mmm space group and unit cell parameter is a = 5.580Å, c = 7.882Å. The primary particles are spherical in shape and the grain size is below 100 nm. The curie temperature is above room temperature and the saturation magnetization is 13.321 A·m2/kg under 1.0 T at room temperature. The sample exhibit typical semiconductor behavior and the conductive mechanism can be described by small polaron variable range hopping model. The room temperature magnetoresistance of the sample under 1.0 T field is up to -10.02%. Moreover, it is found the dosage of citric acid and the amount of reducing agent has great effect on the phase structure and magnetic properties of the samples.

Grain Boundary Effect on Electrical Transport Properties of Graphene

2014 ◽  
Vol 118 (5) ◽  
pp. 2338-2343 ◽  
Author(s):  
Hengji Zhang ◽  
Geunsik Lee ◽  
Cheng Gong ◽  
Luigi Colombo ◽  
Kyeongjae Cho
Keyword(s):  
Grain Boundary ◽  
Transport Properties ◽  
Electrical Transport ◽  
Boundary Effect ◽  
Electrical Transport Properties ◽  
Grain Boundary Effect
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