Influence of synthesis route on the morphology of SrTiO3 particles

2013 ◽  
Vol 1552 ◽  
pp. 51-57
Author(s):  
Marina M. Leite ◽  
Flavio M. Vichi

ABSTRACTThe cubic perovskite SrTiO3 is an important semiconductor oxide with a band gap of 3.2 eV. It has a wide variety of applications such as: dielectric materials, photoluminescent devices, and in photocatalysis. It is conventionally obtained by the classic solid state synthesis (SS), in which TiO2 and SrCO3 react for several hours at temperatures as high as 1200 °C. Besides the high energy demand, SS is not useful for the control of physical characteristics, such as particle size and morphology, which has become essential for some of its applications. It is known that many soft and green routes can produce SrTiO3. Among them, the hydrothermal (HT) and sol-precipitation (SP) methods, as well as the molten salt synthesis (MS) are interesting not only due to their low cost and energy use, but also because of the possibility of particle size and shape control. This study compares the size and morphology of the SrTiO3 particles obtained by these three synthetic pathways. Scanning electron microscopy (SEM) was used to compare particle size and morphology, and X-ray diffraction (XRD) was used to confirm the perovskite formation as well as to determine the Scherrer’s particle size.

2014 ◽  
Vol 1058 ◽  
pp. 15-19 ◽  
Author(s):  
Sheng Jie Yang ◽  
Feng Gao ◽  
Meng Jie Qin ◽  
Qing Qing Zhang ◽  
Xi Xi Huang

Plate-like Sr3Ti2O7powders with anisotropy were prepared by KCl molten salt synthesis (MSS) method, the effect of different SrCO3/TiO2ratio and calcination condition on the phase transition, particle size and morphology of powders were investigated. The results show that SrTiO3phase coexist with Sr3Ti2O7phase and SrTiO3is the main phase as the SrCO3/TiO2ratio is 1.15~1.25:1. Pure Sr3Ti2O7phase can be obtained as the SrCO3/TiO2ratio is 1.55~1.65:1. The aspect ratio of plate-like particles increases firstly and then decreases as the SrCO3/TiO2ratio increases. The sealed and unsealed condition has no influence on the phase structure of the powders. But the aspect ratio of unsealed particles is smaller than that of sealed particle. Finally, the formation mechanism for Sr3Ti2O7particles was discussed.


2014 ◽  
Vol 997 ◽  
pp. 428-432
Author(s):  
Qian Ying Zhang ◽  
Xun Geng

High-quality flaky α-Al2O3 powder with regular morphology, uniform size, larger diameter-thickness proportion and excellent dispersibility in water and free from agglomeration and staggered growth was obtained on the basis of molten salt synthesis method. The effects of experiment parameter on the particle size and morphology of flaky alumina powder were studied. The mechanism of morphology control was discussed.


RSC Advances ◽  
2015 ◽  
Vol 5 (18) ◽  
pp. 13331-13340 ◽  
Author(s):  
T. N. Ng ◽  
X. Q. Chen ◽  
K. L. Yeung

Flow-synthesis of mesoporous silica allows deliberate and precise control over the size and shapes and enables the preparation of complex microstructures (i.e., hollow spheres).


Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 357
Author(s):  
Pedro Moura ◽  
José Ignacio Moreno ◽  
Gregorio López López ◽  
Manuel Alvarez-Campana

University campuses are normally constituted of large buildings responsible for high energy demand, and are also important as demonstration sites for new technologies and systems. This paper presents the results of achieving energy sustainability in a testbed composed of a set of four buildings that constitute the Telecommunications Engineering School of the Universidad Politécnica de Madrid. In the paper, after characterizing the consumption of university buildings for a complete year, different options to achieve more sustainable use of energy are presented, considering the integration of renewable generation sources, namely photovoltaic generation, and monitoring and controlling electricity demand. To ensure the implementation of the desired monitoring and control, an internet of things (IoT) platform based on wireless sensor network (WSN) infrastructure was designed and installed. Such a platform supports a smart system to control the heating, ventilation, and air conditioning (HVAC) and lighting systems in buildings. Furthermore, the paper presents the developed IoT-based platform, as well as the implemented services. As a result, the paper illustrates how providing old existing buildings with the appropriate technology can contribute to the objective of transforming such buildings into nearly zero-energy buildings (nZEB) at a low cost.


2021 ◽  
Vol 11 (14) ◽  
pp. 6578
Author(s):  
Aleksandra Jedlińska ◽  
Alicja Barańska ◽  
Dorota Witrowa-Rajchert ◽  
Ewa Ostrowska-Ligęza ◽  
Katarzyna Samborska

This paper discusses the physicochemical properties of powders obtained by spray drying of cloudy beetroot juice, using dehumidified air in variants with or without carriers. The inlet air temperature was 130 °C or 90 °C, and the addition of the carriers was at a ratio of juice to carrier solids of 3:2. In the obtained powders, the following physicochemical properties were determined: water content and water activity, apparent density, loose and tapped density, porosity, flowability, particle size and morphology, and the content and retention of betalains. It was possible to dry cloudy beetroot juice without the use of carriers at low temperatures (90 or 130 °C). The 100% beetroot powders were characterized by satisfactory physicochemical properties, often better than those with carriers (including lower hygroscopicity and higher color saturation and yield). A lower loss of betalains was found for the powders with the addition of carriers. The best process yields were obtained for the powder without carriers at 130 °C and 90 °C.


2007 ◽  
Vol 336-338 ◽  
pp. 140-142
Author(s):  
Jun Jie Hao ◽  
Xiao Hui Wang ◽  
Shi Yun Lin ◽  
Long Tu Li

Na0.5Bi0.5TiO3 (NBT) is considered to be an excellent candidate for lead-free piezoelectric ceramics. In this study, we propose a hydrothermal method for the preparation of single phase NBT powder at relatively low treatment-temperature. The particle size and morphology of the synthesized powders were examined by SEM. The powders were further pressed into disk and sintered at 1120°C/2h in air, and its properties and microstructure were compared with traditionally prepared samples.


2014 ◽  
Vol 2 (37) ◽  
pp. 15437-15447 ◽  
Author(s):  
Aziz Abdellahi ◽  
Oncu Akyildiz ◽  
Rahul Malik ◽  
Katsuyo Thornton ◽  
Gerbrand Ceder

Using calculations based on first principles, we demonstrate that the preferred interface in singles LiFePO4 particles depends both on the particle size and morphology.


2014 ◽  
Vol 153 ◽  
pp. 130-135 ◽  
Author(s):  
V.M. Lisitsyn ◽  
D.T. Valiev ◽  
I.A. Tupitsyna ◽  
E.F. Polisadova ◽  
V.I. Oleshko ◽  
...  

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