English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We report our Raman studies of a new lead-free relaxor ferroelectrics,Ba0.85Ca0.15Ti0.9Zr0.1O3 (BCTZO). The Raman modes of BCTZO are compared withthose of BaTi0.8Zr0.2O3 (BTZO), and BaTiO3 (BTO). Also, they are compared withthe eigenmodes of BTO calculated by using an ab-initio quantum-mechanicalfrozen-phonon method. The sharp mode at 321 cm-1 of BTO, reported as a coupledmode showing an interference effect, becomes progressively broader in BTZO andBCTZO. This behavior, together with a broadening of the 527-cm-1 mode, suggeststhat the mode-coupling is weakened in BTZO and BCTZO. The structuraltransitions of BCTZO were investigated as functions of pressure at pressuresbelow 20 GPa and of temperature at temperatures below 600 K. Threecharacteristic pressure-induced transitions, on each at 2.5, 5.0, and 13.0 GPa,were found. The transitions are suggested by the drastic changes in phononmodes (two softening modes, one each at ~ 300 and ~ 530 cm-1) and by thetransformation of the intensity profile. A temperature-induced transition wasfound at a Curie temperature of ~ 380 K, where the average structure changesfrom tetragonal to cubic. It is accompanied by a softening mode at ~ 530 cm-1.The phonon spectrum of BCTZO suggests that its local environment is close tothat of BTZO. However, the characteristic pressures of BCTZO are close to thoseof BTO. The sequence of pressure-induced transitions in both BCTZO and BTZOillustrate rich interplay between the long-range averaged structure and theshort-range local order such that four distinguishable phases are suggested:tetragonal, locally ordered but compensated cubic, disordered cubic, and idealcubic. We found that the critical pressures are plausibly related to theaverage crystal lattice.

journal of the korean physical society

Soft Modes and Local Structural Transitions in Pb-free  Ba(Ti0.8Zr0.2)O3-x(Ba0.7Ca0.3)TiO3 (x = 0.5): Pressure- and  Temperature-dependent Raman Studies