scholarly journals B-Site Cation Ordering in Films, Superlattices, and Layer-by-Layer-Grown Double Perovskites

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 734
Author(s):  
Philipp Ksoll ◽  
Christoph Meyer ◽  
Leonard Schüler ◽  
Vladimir Roddatis ◽  
Vasily Moshnyaga

The preparation of cation-ordered thin films of correlated oxides is of great interest for both fundamental and applied research. The scientific long-term vision is strongly motivated by the perspective of studying electronic correlations in condensed matter without the presence of chemical or quenched disorder. A promising material platform provides double perovskite A2BB’O6 bulk samples with different types of B/B’ ordering. However, the growth of A- and/or B-site-ordered correlated oxide thin films is known to be a challenging task. In this review, we evaluate the growth of double perovskite A2BB’O6 thin films by means of well-elaborated physical vacuum deposition techniques, such as pulsed laser deposition (PLD) and sputtering and compare them with a close-to-equilibrium growth with the metalorganic aerosol deposition (MAD) technique. The latter was further developed to grow an emergent interfacial double perovskite phase in LaNiO3/LaMnO3 superlattices, and finally, by way of a layer-by-layer route. The growth of La2CoMnO6 films on SrTiO3(111) substrates by sequential deposition of single perovskite layers of LaCoO3/LaMnO3/LaCoO3/… was demonstrated and the film properties were compared to those obtained within the state-of-the art growth mode.

2017 ◽  
Vol 5 (26) ◽  
pp. 13665-13673 ◽  
Author(s):  
Suttipong Wannapaiboon ◽  
Kenji Sumida ◽  
Katharina Dilchert ◽  
Min Tu ◽  
Susumu Kitagawa ◽  
...  

Addition of a modulator in the LPE process enhances MOF thin film properties by boosting their crystallinity, orientation uniformity, and adsorption capacity.


MRS Advances ◽  
2018 ◽  
Vol 3 (32) ◽  
pp. 1819-1823 ◽  
Author(s):  
Martina Pantaler ◽  
Christian Fettkenhauer ◽  
Hoang L. Nguyen ◽  
Irina Anusca ◽  
Doru C. Lupascu

ABSTRACTThe lead free double perovskite Cs2AgBiBr6 is an upcoming alternative to lead based perovskites as absorber material in perovskite solar cells. So far, the majority of investigations on this interesting material have focused on polycrystalline powders and single crystals. We present vapor and solution based approaches for the preparation of Cs2AgBiBr6 thin films. Sequential vapor deposition processes starting from different precursors are shown and their weaknesses are discussed. Single source evaporation of Cs2AgBiBr6 and sequential deposition of Cs3Bi2Br9 and AgBr result in the formation of the double perovskite phase. Additionally, we show the possibility of the preparation of planar Cs2AgBiBr6 thin films by spin coating.


2016 ◽  
Vol 7 ◽  
pp. 209-219 ◽  
Author(s):  
Nik J Walch ◽  
Alexei Nabok ◽  
Frank Davis ◽  
Séamus P J Higson

In this paper we detail a novel semi-automated method for the production of graphene by sonochemical exfoliation of graphite in the presence of ionic surfactants, e.g., sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB). The formation of individual graphene flakes was confirmed by Raman spectroscopy, while the interaction of graphene with surfactants was proven by NMR spectroscopy. The resulting graphene–surfactant composite material formed a stable suspension in water and some organic solvents, such as chloroform. Graphene thin films were then produced using Langmuir–Blodgett (LB) or electrostatic layer-by-layer (LbL) deposition techniques. The composition and morphology of the films produced was studied with SEM/EDX and AFM. The best results in terms of adhesion and surface coverage were achieved using LbL deposition of graphene(−)SDS alternated with polyethyleneimine (PEI). The optical study of graphene thin films deposited on different substrates was carried out using UV–vis absorption spectroscopy and spectroscopic ellipsometry. A particular focus was on studying graphene layers deposited on gold-coated glass using a method of total internal reflection ellipsometry (TIRE) which revealed the enhancement of the surface plasmon resonance in thin gold films by depositing graphene layers.


2014 ◽  
Vol 4 (1) ◽  
Author(s):  
Shanyong Bao ◽  
Chunrui Ma ◽  
Garry Chen ◽  
Xing Xu ◽  
Erik Enriquez ◽  
...  

2013 ◽  
Vol 7 (1) ◽  
pp. 15-20 ◽  
Author(s):  
Branimir Bajac ◽  
Jelena Vukmirovic ◽  
Ivan Tokic ◽  
Stevan Ognjanovic ◽  
Vladimir Srdic

Presented research was focused on the fabrication of multiferroic thin film structures, composed of ferrielectric barium titanate perovskite phase and magnetostrictive nickel ferrite spinel phase. The applicability of different, solution based, deposition techniques (film growth from solution, dip coating and spin coating) for the fabrication of multilayered BaTiO3 /NiFe2O4 thin films was investigated. It was shown that only spin coating produces films of desired nanostructure, thickness and smooth and crackfree surfaces.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Haijun Wu ◽  
Shoucong Ning ◽  
Moaz Waqar ◽  
Huajun Liu ◽  
Yang Zhang ◽  
...  

AbstractTraditional strategies for improving piezoelectric properties have focused on phase boundary engineering through complex chemical alloying and phase control. Although they have been successfully employed in bulk materials, they have not been effective in thin films due to the severe deterioration in epitaxy, which is critical to film properties. Contending with the opposing effects of alloying and epitaxy in thin films has been a long-standing issue. Herein we demonstrate a new strategy in alkali niobate epitaxial films, utilizing alkali vacancies without alloying to form nanopillars enclosed with out-of-phase boundaries that can give rise to a giant electromechanical response. Both atomically resolved polarization mapping and phase field simulations show that the boundaries are strained and charged, manifesting as head-head and tail-tail polarization bound charges. Such charged boundaries produce a giant local depolarization field, which facilitates a steady polarization rotation between the matrix and nanopillars. The local elastic strain and charge manipulation at out-of-phase boundaries, demonstrated here, can be used as an effective pathway to obtain large electromechanical response with good temperature stability in similar perovskite oxides.


Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1631
Author(s):  
Qiang Zhang ◽  
Yohanes Pramudya ◽  
Wolfgang Wenzel ◽  
Christof Wöll

Metal organic frameworks have emerged as an important new class of materials with many applications, such as sensing, gas separation, drug delivery. In many cases, their performance is limited by structural defects, including vacancies and domain boundaries. In the case of MOF thin films, surface roughness can also have a pronounced influence on MOF-based device properties. Presently, there is little systematic knowledge about optimal growth conditions with regard to optimal morphologies for specific applications. In this work, we simulate the layer-by-layer (LbL) growth of the HKUST-1 MOF as a function of temperature and reactant concentration using a coarse-grained model that permits detailed insights into the growth mechanism. This model helps to understand the morphological features of HKUST-1 grown under different conditions and can be used to predict and optimize the temperature for the purpose of controlling the crystal quality and yield. It was found that reactant concentration affects the mass deposition rate, while its effect on the crystallinity of the generated HKUST-1 film is less pronounced. In addition, the effect of temperature on the surface roughness of the film can be divided into three regimes. Temperatures in the range from 10 to 129 °C allow better control of surface roughness and film thickness, while film growth in the range of 129 to 182 °C is characterized by a lower mass deposition rate per cycle and rougher surfaces. Finally, for T larger than 182 °C, the film grows slower, but in a smooth fashion. Furthermore, the potential effect of temperature on the crystallinity of LbL-grown HKUST-1 was quantified. To obtain high crystallinity, the operating temperature should preferably not exceed 57 °C, with an optimum around 28 °C, which agrees with experimental observations.


2020 ◽  
Vol 11 (24) ◽  
pp. 10548-10551
Author(s):  
Aswani Sathish Lathika ◽  
Shammi Rana ◽  
Anupam Prasoon ◽  
Pooja Sindhu ◽  
Debashree Roy ◽  
...  

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