Room-temperature ferromagnetism and optical properties in Mg-doped TiO2: A density functional theory investigation

2014 ◽  
Vol 115 (12) ◽  
pp. 123913 ◽  
Author(s):  
Yanyu Liu ◽  
Wei Zhou ◽  
Ping Wu
2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Daniel Fritsch

In recent years, much effort has been devoted to replace the most commonly used piezoelectric ceramic lead zirconate titanate Pb[ZrxTi1−x]O3 (PZT) with a suitable lead-free alternative for memory or piezoelectric applications. One possible alternative to PZT is sodium niobate as it exhibits electrical and mechanical properties that make it an interesting material for technological applications. The high-temperature simple cubic perovskite structure undergoes a series of structural phase transitions with decreasing temperature. However, particularly the phases at room temperature and below are not yet fully characterised and understood. Here, we perform density functional theory calculations for the possible phases at room temperature and below and report on the structural, electronic, and optical properties of the different phases in comparison to experimental findings.


RSC Advances ◽  
2015 ◽  
Vol 5 (42) ◽  
pp. 33674-33680 ◽  
Author(s):  
Gul Rahman

Density functional theory with local spin density approximation has been used to propose possible room temperature ferromagnetism in N-doped NaCl-type BaO.


2016 ◽  
Vol 78 (3) ◽  
Author(s):  
A. M. A. Bakheet ◽  
M. A. Saeed ◽  
Riadh Sahnoun ◽  
A. R. M. Isa ◽  
Lawal Mohammed ◽  
...  

 β-Tri-calcium phosphate material (β-TCP), have attract a wide interest in the material science and medical science applications, due to its excellent biocompatibility and its identical chemical compositions to the natural teeth and bones. For that reason, (β-TCP) compound is widely used as biocompatible ceramics in medical and dental science applications. However, research shows that, pure β-TCP material has lower ability to stimulate the growth of natural bone and teeth as needed. Therefore, in order to address this deficiency magnesium impurity is used to replace calcium in the matrix of pure β-TCP to enhance its electronic and optical properties which are not present in the pure one. Thereby, its biological performance becomes improved. By changing the chemical composition of β-TCP to be similar to the mineral compositions of the natural teeth and bones. This will give more insight in fabrication of biomaterial devices for replacing, repairing and rebuilding the broken or damaged human teeth and bones. Here, we present the study of compound β-TCP using density functional theory (DFT). For the calculations, we used full potential linear augmented plane wave method (FPL-APW), along with generalized gradient approximations (GGA) potential. The band gap values of 5.2 eV and 3.4 eV are obtained for the pure and Mg-doped β-TCP, respectively. These results are in good agreement with the experimental values. Our results show peaks which correspond to the refractive index, complex dielectric function, optical conductivity, optical reflectivity, extinction coefficient, absorption efficient, and electron energy loss. These peaks are shifted towards the higher energy values for the pure and Mg-doped β-TCP material. The obtained results have more significance for increasing the quality of electronic and optical properties of this material and offer more evidences to synthesize enhanced β-TCP material for dental and medical applications.


2021 ◽  
Vol 551 ◽  
pp. 149479
Author(s):  
Herman Heffner ◽  
Ricardo Faccio ◽  
Ignacio López–Corral

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abdur Rauf ◽  
Muhammad Adil ◽  
Shabeer Ahmad Mian ◽  
Gul Rahman ◽  
Ejaz Ahmed ◽  
...  

AbstractHematite (Fe2O3) is one of the best candidates for photoelectrochemical water splitting due to its abundance and suitable bandgap. However, its efficiency is mostly impeded due to the intrinsically low conductivity and poor light absorption. In this study, we targeted this intrinsic behavior to investigate the thermodynamic stability, photoconductivity and optical properties of rhodium doped hematite using density functional theory. The calculated formation energy of pristine and rhodium doped hematite was − 4.47 eV and − 5.34 eV respectively, suggesting that the doped material is thermodynamically more stable. The DFT results established that the bandgap of doped hematite narrowed down to the lower edge (1.61 eV) in the visible region which enhanced the optical absorption and photoconductivity of the material. Moreover, doped hematite has the ability to absorb a broad spectrum (250–800) nm. The enhanced optical absorption boosted the photocurrent and incident photon to current efficiency. The calculated results also showed that the incorporation of rhodium in hematite induced a redshift in optical properties.


2021 ◽  
pp. 413061
Author(s):  
Shahran Ahmed ◽  
Sadiq Shahriyar Nishat ◽  
Alamgir Kabir ◽  
A.K.M. Sarwar Hossain Faysal ◽  
Tarique Hasan ◽  
...  

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