Improved Deposition Process of CVD-(Ba,Sr)TiO3 on Ru

2000 ◽  
Vol 655 ◽  
Author(s):  
M. Tarutani ◽  
T. Sato ◽  
M. Yamamuka ◽  
T. Kawahara ◽  
T. Horikawa ◽  
...  

Abstract(Ba,Sr)TiO3 [BST] films were deposited by the flash vaporization CVD method with a unique liquid delivery system. An inductively coupled plasma mass spectrometry [ICP-MS] analysis revealed the decline of (Ba+Sr)/Ti molar ratio of the initial BST-layer on Ru. By readjusting the flow ratio of liquid sources and using a two-step deposition method, we obtained 30-nm-thick BST films with uniform composition profile, exhibiting good electrical properties. The leakage property, however, was severely deteriorated in BST films less than 24 nm thick. A SEM observation showed the presence of micro-roughness or micro-hillocks in these films, which were confirmed to be caused by Ru oxidation. Therefore, an annealing process of the Ru electrode was added for its planarization, and the CVD process was also improved. As a result, we obtained smooth and finely crystallized ∼ 20-nm-thick BST films with good electrical properties of equivalent SiO2 thickness (teq) ∼ 0.45 nm and leakage current < 1 × 10−7 A/cm2. We also measured properties of BST films deposited on the 3-D Ru electrode. The results are briefly discussed.

2002 ◽  
Vol 56 (9) ◽  
pp. 1152-1160 ◽  
Author(s):  
Xiaohua Zhang ◽  
John A. Koropchak

Thermospray (TSP) coupled with inductively coupled plasma-atomic emission spectroscopy (ICP-AES) or inductively coupled plasma-mass spectrometry (ICP-MS) has been developed as a non-chromatographic method for chromium speciation to quantitatively separate and determine two chromium oxidation states: Cr(III) and Cr(VI). The limits of detection can reach 0.5 ng/mL with ICP-AES detection and 50 pg/mL with ICP-MS detection. The basis for this speciation method is that Cr(III) can selectively and nearly quantitatively deposit inside a thermospray system as Cr2O3, while Cr(VI) does not. To fully understand the mechanism of this deposition process, four questions were investigated: is aerosol formation necessary for the reaction to occur? Does the deposition occur in the aerosol or liquid regime? Does the deposit tend to be retained on the surface of the fused silica capillary? Can the reaction be predicted from thermodynamic calculations? These studies show that this reaction happens before solvent evaporates (i.e., the liquid regime). The high temperature inside the thermospray system is the major factor triggering this reaction. At the same time, the high pressure is important for its influence on the solvent boiling point, which affects the residence time (the time that the analyte spends in the solution before the solvent evaporates) and the kinetics of the reaction. The effects of the other parameters (vaporizer length, heating length, drawn tip, etc.) on the efficiency of the deposition reaction, represented as background residual signal (BRS), were also studied.


Crystals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 98 ◽  
Author(s):  
Sijia Wang ◽  
Zengzhe Xi ◽  
Pinyang Fang ◽  
Xiaojuan Li ◽  
Wei Long ◽  
...  

A single crystal with nominal composition Pb(Mg1/3Nb2/3)O3-32PbTiO3 (PMN-32PT) was grown by the Bridgman technique. Crystal orientation was determined using the rotating orientation X-ray diffraction (RO-XRD). Element distribution was measured along different directions using inductively coupled plasma-mass spectrometry (ICP-MS). The effect of the element segregation along axial and radial directions on the electrical properties of the PMN-32PT crystal was investigated. It is indicated that the electrical properties of the samples along the axial direction were strongly dependent on the PT (PbTiO3) content. With the increase of the PT content, the piezoelectric coefficient and remnant polarization were improved. Differently, the electrical properties of the samples along the radial direction were mainly determined by the ratio of the Nb and Mg. The reasons for the element segregation and electrical properties varied with the composition were discussed.


2021 ◽  
Vol 947 (1) ◽  
pp. 012027
Author(s):  
Tuyet-Mai Tran-Thuy ◽  
Ngoc-Thuy Nguyen-Thi ◽  
Trong-Phu Tran ◽  
Ngoc-Hung Tran-Le ◽  
Minh-An Dang ◽  
...  

Abstract K-OMS-2 (non-modified sample) and Ce-modified OMS-2 with different Ce-loading amounts were prepared by the refluxed method. The cryptomelane structure and elemental composition of synthesized samples were characterized with X-ray diffraction (XRD) and inductively coupled plasma mass spectrometry (ICP-MS), respectively. ICP-MS analysis revealed ~0.06 – 0.11 of K/Mn molar ratio and the Ce-loading amounts increased from 0 to —11.27 wt.% under increasing Ce-precursor concentration. Antibacterial activity against Pseudomonas aeruginosa was evaluated by the agar well diffusion method. The antibacterial ability against Pseudomonas aeruginosa was not recorded over K-OMS-2 (Ce0; 4.5 wt.% of K; 0 wt.% of Ce) and Ce3 (0.89 wt.% of K; 11.27 wt.% of Ce) samples while Ce2 sample (1.89 wt.% of K; 8.7 wt.% of Ce) showed a comparable antibacterial activity against Pseudomonas aeruginosa with ~12 mm of inhibition-zone diameter. This suggested the potentiality of using metal-modified cryptomelane in acceleration of antimicrobial ability.


2019 ◽  
Author(s):  
Ingo Strenge ◽  
Carsten Engelhard

<p>The article demonstrates the importance of using a suitable approach to compensate for dead time relate count losses (a certain measurement artefact) whenever short, but potentially strong transient signals are to be analysed using inductively coupled plasma mass spectrometry (ICP-MS). Findings strongly support the theory that inadequate time resolution, and therefore insufficient compensation for these count losses, is one of the main reasons for size underestimation observed when analysing inorganic nanoparticles using ICP-MS, a topic still controversially discussed.</p>


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