LaNiO3 films with tunable out-of-plane lattice parameter and their strain-related electrical properties

2015 ◽  
Vol 212 (9) ◽  
pp. 1925-1930 ◽  
Author(s):  
Haoming Wei ◽  
Marcus Jenderka ◽  
Marius Grundmann ◽  
Michael Lorenz
2000 ◽  
Vol 619 ◽  
Author(s):  
T. Steffl ◽  
B. Rellinghaus ◽  
H. Mühlbauer ◽  
CH. Müller ◽  
H. Herper ◽  
...  

ABSTRACTWe have prepared (Fe(001)/Pd(001)) multilayers onto Pd-buffered sapphire substrates. Structural investigations utilizing HRTEM, RHEED and XRD show that the films grow epitaxially for up to 32 bilayers. Whereas the Fe lattice is found to assume the lateral (in-plane) lattice spacing of the underlying Pd layers, the out-of-plane lattice parameter along the [001] growth direction of the film is successively reduced with increasing Fe layer thickness. This outof-plane lattice relaxation even survives a subsequent growth of Pd onto the Fe. Thus, by varying the Fe layer thickness we have control of the atomic volume of Fe. Magnetization measurements reveal that the magnetic moment of Fe is as high as 2.7 µB per atom when the atomic volume is larger than Vat(Fe) ≥ 11.7 Å3 and is reduced to 2.2 µB per atom for Vat(Fe) ≤ 11.1 Å3.


1994 ◽  
Vol 354 ◽  
Author(s):  
P. Partyka ◽  
R.S. Averback ◽  
D.V. Forbes ◽  
J.J. Coleman ◽  
P. Ehrhart ◽  
...  

AbstractRadiation-induced damage and strain in AlxGai-xAs (x=5 to 1) were investigated by measurements of the lattice parameter using x-ray diffraction. Irradiations employed MeV C, Ar and Au ion beams with a substrate temperature of 80 K. For samples with high Al content, the out-of-plane lattice parameter increased with fluence at low doses, saturated, and then decreased to nearly its original value. The in-plane lattice parameter did not change, throughout. These results were independent of the irradiation particle when scaled by damage energy. For the Al.5Ga.5As samples, however, the out-of-plane lattice parameter increased monotonically with dose to large strains until the layer amorpnized. Selected samples were examined by high resolution and conventional transmission electron microscopy (TEM). Channeling Rutherford backscattering spectrometry (CRBS) was also employed to monitor the buildup of damage in many samples. Recovery of the lattice parameter during subsequent thermal annealing was also investigated.


1999 ◽  
Vol 14 (7) ◽  
pp. 2905-2911 ◽  
Author(s):  
Sangsub Kim ◽  
Tae Soo Kang ◽  
Jung Ho Je

Epitaxial (Ba0.5Sr0.5) TiO3 thin films of two different thickness (∼25 and ∼134 nm) on MgO(001) prepared by a pulsed laser deposition method were studied by synchrotron x-ray scattering measurements. The film grew initially with a cube-on-cube relationship, maintaining it during further growth. As the film grew, the surface of the film became significantly rougher, but the interface between the film and the substrate did not. In the early stage of growth, the film was highly strained in a tetragonal structure (c/a = 1.04) with the longer axis parallel to the surface normal direction. As the growth proceeded further, it relaxed to a cubic structure with the lattice parameter near the bulk value, and the mosaic distribution improved significantly in both in- and out-of-plane directions. The thinner film (∼25 nm) showed only one domain limited mainly by the film thickness, but the thicker film (∼134 nm) exhibited three domains along the surface normal direction.


2021 ◽  
Vol 11 (4) ◽  
pp. 12215-12226

Undoped, Cerium (Ce) doped, Manganese (Mn) doped and Ce-Mn co-doped Barium Titanate (BaTiO3) with the general formula Ba1-xCexMnyTi1-yO3 (where x = 0.00, 0.01, 0.02, 0.03, y = 0.00; x = 0.00, y =0.01, 0.02, 0.03; and x = y = 0.01, 0.02,0.03) were synthesized by solid-state reaction method and sintered at 1200 C for 4 hr with an aim to study their structural and electrical properties. The grain size of the samples has been estimated using the Scanning Electron Microscopy (SEM). The X-ray Diffraction (XRD) analysis indicates that the structure of the Ce-doped and Ce-Mn co-doped BaTiO3 is cubic. However, the undoped BaTiO3 and Mn-doped BaTiO3 confirmed the tetragonal-cubic mixed phases. With the change of doping concentrations, the positions of different peaks shifted slightly. The lattice parameter varied irregularly with increasing doping concentration because of Mn's changeable valency. EDX spectra confirmed the presence of Ba, Ti, Ce, and Mn contents in the co-doped samples with stoichiometric ratio. Crystallinity is observed to be clearly increased when Ce-Mn is co-doped in BaTiO3. J-V characteristic curves indicate transition from conducting to semiconducting nature for the doped and co-doped samples with the increase in temperature. The dielectric constant of the samples increases up to 4500 with the doping concentration. The higher values of dielectric constant are observed for the 2% Mn-doped and 1% Ce-Mn co-doped samples compared to the other undoped samples. For the undoped and Mn-doped samples, constant dielectric values increase with temperature but decrease for the Ce-doped and Ce-Mn co-doped samples. It is inferred that co-doping of BaTiO3 with Ce and Mn would be beneficial and economical for its applications.


2014 ◽  
Vol 38 (1) ◽  
pp. 7-18 ◽  
Author(s):  
Sheikh Mohi Uddin Rumy ◽  
Mahabub Alam Bhuiyan ◽  
MH Mesbah Ahmed ◽  
Kazi Hanium Maria ◽  
MA Hakim ◽  
...  

The effects of Li2O additives on the structural, magnetic and electrical properties of Ni0.5Mg0.5Fe2O4, prepared by conventional double sintering ceramic technique were investigated. The X-raydiffraction (XRD) pattern of the prepared samples showed single phase cubic spinel structure.Variation of lattice parameter has been observed with the variation of Li2O content. Theenhancement of bulk density has been observed for 2 mol% Li2O additive, but further increase inLi2O concentration, these values decrease. Enhancement of initial permeability (??) have beenobserved for the sample with 2 mol% Li2O additives while it decreases for higher concentration ofLi2O. The Curie temperature is found to decrease with the increase in Li2O additive. The resistivityincreases with increasing additive content and showed a significant dispersion with frequency,which is the normal ferromagnetic behavior. The dielectric constant (??) measurement showed thenormal dielectric behavior of spinel ferrite. Possible explanation for the observed features arediscussed. DOI: http://dx.doi.org/10.3329/jbas.v38i1.20198 Journal of Bangladesh Academy of Sciences, Vol. 38, No. 1, 7-18, 2014


2017 ◽  
Vol 58 (6) ◽  
pp. 852-856 ◽  
Author(s):  
Hiroyuki Nakayama ◽  
Kimihiro Ozaki ◽  
Takuji Nabeta ◽  
Yasushi Nakajima

2013 ◽  
Vol 709 ◽  
pp. 172-175
Author(s):  
Li Lv ◽  
Min Zhang ◽  
Li Qin Yang ◽  
Xin Sheng Yang ◽  
Yong Zhao

Single crystals of Bi2Se3 topological insulators have been prepared though melt-grown reaction. The sintering parameters of holding time and cooling rate obviously affect the phase structure and electrical properties. The samples with layered structure can be perpendicular cleaved with (0 0 L) axis. All the samples show n-type conductivity caused by the existence of Se vacancies. For low cooling rate, more Se atoms anti-occupy Bi lattice sites, which decreases c-axis lattice parameter and increases carrier concentration n; high cooling rate increases c and decreases n because of less Se atoms occupying Bi lattice sites. Increasing holding time firstly decreases the ratio of Se atoms occupying Bi lattice sites and then increases it, which gives rise to c firstly increase then decrease and n firstly decrease then increase.


2014 ◽  
Vol 979 ◽  
pp. 302-306 ◽  
Author(s):  
Chalermpol Rudradawong ◽  
Aree Wichainchai ◽  
Aparporn Sakulkalavek ◽  
Yuttana Hongaromkid ◽  
Chesta Ruttanapun

In this paper, the CuFeO2compound were prepared by classical solid state reaction (CSSR) and direct powder dissolved solution (DPDS) method from starting material metal oxides and metal powders. Preparation of two methods shows that, direct powder dissolved solution faster recover phases than classical solid state reaction method. The fastest method gets from starting materials Cu and Fe metal powders, the electrical conductivity, Seebeck coefficient, carrier concentration and mobility are 10.68 S/cm, 244.59 μV/K, 12.86×1016cm-3and 494.96 cm2/V.s, respectively. In addition, each CuFeO2compounds were investigated on crystal structure and electrical properties. From XRD and SEM results, all samples have a crystal structure delafossite-typeand a large grain boundary more than 15 μm by electrical conductivity corresponds to grain boundary and lattice parameter: a increases. Within this paper, from above results exhibit that preparation CuFeO2from Cu and Fe by direct powder dissolved solution method most appropriate for thermoelectric oxide materials due to high active for preparation else high lattice strain and high power factor are 0.00052 and 0.64×10-4W/mK2, respectively.


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