Effects of Individual Layer Thickness on the Structure and Electrical Properties of Sol-Gel-Derived Ba0.8Sr0.2TiO3 Thin Films

2012 ◽  
Vol 621 ◽  
pp. 23-26
Author(s):  
Wei Rao ◽  
Ding Guo Li ◽  
Hong Chun Yan
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Layer Thickness ◽  
Sol Gel ◽  
Layer By Layer ◽  
Individual Layer ◽  
Individual Layer Thickness ◽  
Columnar Grains ◽  
The Individual ◽  
20 Nm

Ba0.8Sr0.2TiO3 thin films were prepared with various individual layer thicknesses using a sol– gel process. The individual layer thickness strongly affected the structure, ferroelectricity, and dielectric properties of the films. The films prepared with an individual layer thickness of 60 nm showed small equiaxed grains, cubic structure, temperature-independent dielectric constant, and no ferroelectricity. The films prepared with an individual layer thickness of 8 nm showed columnar grains, tetragonal structure, good ferroelectricity, and two dielectric peaks in the dielectric constant–temperature curve. The individual layer thickness for layer-by-layer homoepitaxy growth that resulted in columnar grains was <20 nm.

Effect of Annealing on Structural Properties of Co Thin Films and Co/Cu Multilayers

2004 ◽  
Vol 443-444 ◽  
pp. 193-196 ◽  
Author(s):  
M. Hecker ◽  
N. Mattern ◽  
W. Brückner ◽  
C.M. Schneider
Keyword(s):  
Thin Films ◽  
Layer Thickness ◽  
Strong Increase ◽  
Complete Disappearance ◽  
Individual Layer ◽  
In Situ Xrd ◽  
Individual Layer Thickness ◽  
Weak Preference ◽  
Grain Orientations ◽  
The Individual

The subject of the present investigation is the influence of annealing on the microstructure of Co thin films. In particular, the evolution of the texture during annealing is studied and compared with that of Co/Cu multilayers of different individual layer thicknesses. 400nm thick Co films show a h.c.p. structure with a weak preference of the <001> texture component and a broad distribution of grain orientations. Annealing at about 350°C results in a strong increase of the h.c.p. <001> component, nearly complete disappearance of the statistical distribution and grain growth of a minor f.c.c. fraction in the films. In-situ XRD measurements on single Co films during annealing confirm that the texture change is irreversible. Multilayer stacks of Co/Cu layers show various texture changes depending on the individual layer thickness (ranging between 100nm and 1nm). Generally, with decreasing individual layer thickness and increasing annealing temperature the f.c.c. content in the multilayers increases at the expense of the h.c.p. fraction.

Effects of Individual Layer Thickness on the Structure and Electrical Properties of Sol-Gel-Derived Ba0.8Sr0.2TiO3 Thin Films

2004 ◽  
Vol 83 (10) ◽  
pp. 2616-2618 ◽  
Author(s):  
Jian-Gong Cheng ◽  
Xiang-Jian Meng ◽  
Jun Tang ◽  
Shao-Ling Guo ◽  
Jun-Hao Chu ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Layer Thickness ◽  
Sol Gel ◽  
Individual Layer ◽  
Individual Layer Thickness

Internal Stress In Sputtered Silver Nickel Thin Films And Multilayers: Sputtering Pressure And Thickness Effects

1999 ◽  
Vol 562 ◽  
Author(s):  
P. Gergaud ◽  
H. Yang ◽  
C. PéLissonnier-Grosjean ◽  
A. J. Bottger ◽  
P. Sandström ◽  
...  
Keyword(s):  
Thin Films ◽  
Internal Stress ◽  
Layer Thickness ◽  
Lattice Parameter ◽  
Free Lattice ◽  
Silicon Substrates ◽  
X Ray Diffraction ◽  
Nickel Thin Films ◽  
The Individual ◽  
20 Nm

ABSTRACTNanometer thick films are often in a state of high residual stress. This may strongly influence physical properties such as magnetic anisotropy. The aim of our study is to investigate whether the overall stress in multilayers may be tailored via the control of the sputtering parameters or of the individual thicknesses. The coatings investigated were deposited at room temperature by magnetron sputtering on oxidised silicon substrates. Ag/Ni multilayers of superperiod between 4 to 20 nm and thin films (Ag or Ni) 200 nm thick have been deposited under a krypton partial pressure varying between 1 and 8 mTorr. Internal stress measurements were performed by curvature method and x-ray diffraction sin2ψ method. The latter one allows the determination of the stress and of the stress-free lattice parameter in the Ag or the Ni layers whereas the first one gives rise to a measure of the average stress in the coating. The main results are the followings: (i) The stress in Ni thin films changes from compressive to tensile at a pressure between 2 and 5 mTorr whereas Ag thin films are sligthly tensile whatever the pressure; (ii) The stress in multilayers is tensile in Ag and Ni and decreases with sublayer thickness; (iii) The stress free lattice parameter of Ag in thin films or multilayers is independent of the Kr pressure and of the layer thickness and is equal to the bulk value; (iv) On the opposite, the stress-free lattice parameter of nickel decreases with the layer thickness in multilayers and is equal to the bulk value in thin films. These results are discussed in terms of the respective influence of interfacial intermixing and atomic peening mechanism.

Effect of the individual layer thickness on the transformation of Cu/W nano-multilayers into nanocomposites

Materialia ◽  
2019 ◽  
Vol 7 ◽  
pp. 100400 ◽  
Author(s):  
A.V. Druzhinin ◽  
D. Ariosa ◽  
S. Siol ◽  
N. Ott ◽  
B.B. Straumal ◽  
...  
Keyword(s):  
Layer Thickness ◽  
Individual Layer ◽  
Individual Layer Thickness ◽  
The Individual

Sol-Gel Derived Pyroelectric Barium Strontium Titanate Thin films for Infrared Detector Applications

2000 ◽  
Vol 655 ◽  
Author(s):  
Jian-Gong Cheng ◽  
Jun Tang ◽  
Shao-Ling Guo ◽  
Jun-Hao Chu
Keyword(s):  
Thin Films ◽  
Electrode Materials ◽  
Infrared Detector ◽  
Sol Gel ◽  
Precursor Solution ◽  
Columnar Structure ◽  
Silicon Substrates ◽  
Layer By Layer ◽  
Individual Layer ◽  
Sol Gel Process

AbstractBa0.8Sr0.2TiO3 thin films that are suitable for infrared detector applications have been prepared with a sol-gel process using a highly diluted precursor solution. Columnar structure with grain size close to 200 nm was obtained with layer-by-layer homoepitaxy due to a very small thickness of individual layer. The measured pyroelecrtic coefficient is larger than 3.1×10划4 C/m2K at the temperatures ranging from 10 to 26 °C and reaches the maximum value of 4.1×10划4 C/m2K at 16.8 °C. The infrared detectivity of 4.6×107 cmHz1/2W划1 has been obtained at 19 °C and 10 Hz in the Ba0.8Sr0.2TiO3 films deposited on thick (500 μm) platinum coated silicon substrates. The better infrared response can be expected by the improvement in the thermal isolation of pyroelectric element and the electrode materials.

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