Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

This eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contact

Ionic Liquids --- Solvent effect --- Structural investigation --- functional materials --- Catalysis

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

This eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contact

Civil engineering, surveying & building --- Mechanical engineering & materials --- functional materials --- biological --- biomedical --- bioinspired composites --- multiscale composites --- functional materials --- biological --- biomedical --- bioinspired composites --- multiscale composites

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

This special collection provides up-to-date knowledge concerning the field of functional materials such as shape memory alloys, piezoelectric ceramics and aluminium alloys. The articles therein also deal with recent investigations of quasicrystals and geopolymers: two classes of hybrid material that have attracted great scientific interest, given their unusual properties and potential engineering applications. In the first part, the papers address key issues concerning the application of two classes of functional alloy: (i) NiTi alloys, having important applications in the fields of smart stru

Materials science --- Shape memory alloys --- Piezoelectric ceramics --- Aluminum alloys --- Ceramics --- Piezoelectricity --- Alloys --- Smart materials --- Functional materials

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

This eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contact

Science: general issues --- Ionic Liquids --- Solvent effect --- Structural investigation --- functional materials --- Catalysis

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

In this study, I investigate layered oxide perovskites, specifically n=2 Dion-Jacobson phases with the formula AA′B2O7, using first-principles Density Functional Theory simulations. These materials are of interest due to their potential ferroelectric properties but are often under-explored and poorly characterized. I carefully calculate the force constants associated with phonon modes by utilizing the frozen-phonon technique in the symmetry-adapted mode basis. The coupling of different phonon modes happens only if it is symmetry-allowed, giving a natural tool to study phase transitions. Unstable modes are identified by a negative force constant; the eigenvalues of these modes can be frozen into the structure, which, after relaxation, results in a more stable material. The materials studied in this work are compounds with the formula ANdNb2O7 where A is Rb, Na, or NH4 cation. The ammonia molecule-containing phase is the primary compound of this study. The presence of various unstable phonon modes complicates the prediction of a definitive ground state; thus, I present several potential lower symmetry structures derived from the aristotype. These models serve as a basis for further experimental characterization and enhance our understanding of structure-property relationships, particularly the influence of aspherical cations on the material’s ground state structure. This research provides foundational insights into the dynamic properties of layered perovskites, paving the way for future studies on their practical applications in ferroelectric and other functional materials.

First-priciples --- Perovskite --- Functional materials --- Phase transition --- Physique, chimie, mathématiques & sciences de la terre > Physique