scholarly journals Multiferroic and Optical Properties of La0.05Li0.85NbO3 and LiNbO3 Nanocrystals

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Carlos A. Díaz-Moreno ◽  
Jorge A. López ◽  
Yu Ding ◽  
A. Hurtado Macias ◽  
Chunqiang Li ◽  
...  

The chemistry and physics of surfaces is an increasingly important subject. The study of surfaces is the key of many important nanotechnological applications due to the understanding of phase transitions, electronic structure, and chemical bonding. In later years, exotic phenomena that jointly involve the magnetic and electrical conductivity properties have been discovered in oxides that contain magnetic ions. Moreover, the uses of magnetic oxides in electronic technology have become so important due to the miniaturization of devices and magnetic materials with dielectric properties or vice versa being required for inductors, information storage, thin films for high-density computer memories, microwave antireflection coatings, and permanent magnets for automobile ignitions among others. On the contrary, nanotechnology developments over 10 years or so have provided intensive studies in trying to combine properties such as ferroelectric, ferromagnetic, and optics in one single-phase nanoparticles or in composite thin films; this last effort has been recently known as multiferroic. Because of this, the resurgence of nanomaterials with multiferroic and optical properties is presented in this work of one single phase in lanthanum lithium niobate (La0.05Li0.85NbO3) and lithium niobate (LiNbO3) with ferromagnetic, ferroelectric, relaxor ferroelectricity, second harmonic generation, high-temperature ferromagnetic, and magnetoelectric properties.

2020 ◽  
Vol 117 (46) ◽  
pp. 28589-28595 ◽  
Author(s):  
Chiara Gattinoni ◽  
Nives Strkalj ◽  
Rea Härdi ◽  
Manfred Fiebig ◽  
Morgan Trassin ◽  
...  

Ferroelectric perovskites present a switchable spontaneous polarization and are promising energy-efficient device components for digital information storage. Full control of the ferroelectric polarization in ultrathin films of ferroelectric perovskites needs to be achieved in order to apply this class of materials in modern devices. However, ferroelectricity itself is not well understood in this nanoscale form, where interface and surface effects become particularly relevant and where loss of net polarization is often observed. In this work, we show that the precise control of the structure of the top surface and bottom interface of the thin film is crucial toward this aim. We explore the properties of thin films of the prototypical ferroelectric lead titanate (PbTiO3) on a metallic strontium ruthenate (SrRuO3) buffer using a combination of computational (density functional theory) and experimental (optical second harmonic generation) methods. We find that the polarization direction and strength are influenced by chemical and electronic processes occurring at the epitaxial interface and at the surface. The polarization is particularly sensitive to adsorbates and to surface and interface defects. These results point to the possibility of controlling the polarization direction and magnitude by engineering specific interface and surface chemistries.


1996 ◽  
Author(s):  
Dexin X. Lu ◽  
Emile M. W. Wong ◽  
Edwin Y. B. Pun ◽  
Po Sheun Chung

2019 ◽  
Vol 45 (1) ◽  
pp. 145
Author(s):  
Junjun Ma ◽  
Jiaxin Chen ◽  
Mengxin Ren ◽  
Wei Wu ◽  
Wei Cai ◽  
...  

2008 ◽  
Vol 517 (2) ◽  
pp. 603-608 ◽  
Author(s):  
V. Jayasree ◽  
R. Ratheesh ◽  
V. Ganesan ◽  
V.R. Reddy ◽  
C. Sudarsanakumar ◽  
...  

2020 ◽  
Vol 238 ◽  
pp. 05003
Author(s):  
Flavia Timpu ◽  
Helena Weigand ◽  
Fabian Kaufmann ◽  
Felix U. Richter ◽  
Viola-Valentina Vogler-Neuling ◽  
...  

We present the design and fabrication advances on active lithium niobate metasurfaces. We determine by numerical calculations a metasurface design with electro-magnetic resonances in the visible and near-infrared, by taking into account the constraints for fabrication on thin films of lithium niobate. We suggest that the optical properties of the metasurface can be switched using the electro-optical properties of lithium niobate.


Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1840
Author(s):  
Dong Xu ◽  
Qian Yu ◽  
Taiyun Chen ◽  
Sujuan Zhong ◽  
Jia Ma ◽  
...  

ZnO porous thin films were synthesized as antireflection coatings via a sol–gel dip-coating method with polyethylene glycol (PEG1000) utilized as a polymeric porogen on alumina transparent ceramics. The pore formation mechanism of the ZnO porous thin films was proposed through thermal and Fourier transformation infrared spectrometer (FTIR) analyses. The effect of sol concentrations on crystal structure, microstructure, and optical properties was also discussed. The experiment results indicated that all the ZnO thin films exhibited a hexagonal wurtzite structure with their preferred orientation along a (0 0 2) plane by X-ray diffraction (XRD) patterns. The grain size of the films increased from 30.5 to 37.4 nm with the sol concentration ranging from 0.2 to 1.0 M. Furthermore, scanning electron microscopy (SEM) images show that the pores on the surface were observed to first decrease as the sol concentration increased and then to disappear as the sol concentration continued to increase. The UV spectrum presents a maximum transmittance of 93.5% at a wavelength of 600 nm at a concentration of 0.6 M, which will be helpful in the practical applications of ZnO porous film on alumina transparent ceramic substrates. The pore formation mechanism of ZnO porous thin films can be ascribed to ring-like network structures between the PEG1000 and zinc oligomers under the phase separation effect.


2015 ◽  
Vol 1109 ◽  
pp. 544-548 ◽  
Author(s):  
Jian Bo Liang ◽  
Xu Yang Li ◽  
Naoki Kishi ◽  
Tetsuo Soga

Single phase CuO films have been successfully synthesized by thermal oxidation of cupper foil in air with water vapor. The structural and optical properties of CuO films were investigated. It is observed that the grain size increases with increasing the oxidation temperature. The optical band gap of CuO film is determined by the transmittance and reflectance spectra.


2021 ◽  
Vol 12 (2-2021) ◽  
pp. 72-76
Author(s):  
D. A. Vorobev ◽  
◽  
O. V. Sidorova ◽  
M. N. Palatnikov ◽  
A. V. Kadetova ◽  
...  

The coefficients of the second-order nonlinear optical tensor for lithium niobate crystal with a composition close to stoichiometric were calculated. The calculated results show that the contribution of the Li-O group to the optical effects of the second harmonic was greater than the contribution of the Nb-O group. The results also showed that the most efficient frequency conversion occurred along the polar axis of the crystal


Sign in / Sign up

Export Citation Format

Share Document