8 research outputs found
Investigation of structural, magnetic and dielectric properties of Cr3+ substituted Cu0.75Co0.25Fe2-xO4 ferrite nanoparticles
No full textOrigin of giant dielectric permittivity and weak ferromagnetic behavior in (1−x)LaFeO3−xBaTiO3 (0.0 ≤ x ≤ 0.25) solid solutions
No full textThe solid solutions of (1−x) LaFeO3–xBaTiO3 (0.0≤x≤0.25) have been synthesized successfully by the conventional solid-state reaction method. Room temperature (RT) X-ray diffraction studies reveal the stabilization of orthorhombic phase with Pbnm space group. Complete solubility in the perovskite series was demonstrated up to x=0.25. The dielectric permittivity shows colossal dielectric constant (CDC) at RT. The doping of BaTiO3 in LaFeO3 exhibit pronounced CDC up to a composition x=0.15, further it starts to decrease. The frequency-dependent dielectric loss exhibits polaronic conduction, which can attribute to presence of multiple valence of iron. The relaxation frequency and polaronic conduction mechanism was shifted towards RT as function of x. Moreover, large magnetic moment with weak ferromagnetic behavior is observed in doped LaFeO3 solid solution, which might be the destruction of spin cycloid structure due to insertion of Ti in Fe–O–Fe network of LaFeO3
Energy storage, electrocaloric and optical property studies in Ho-modified NBT – BT lead-free ferroelectric ceramics
No full textA comprehensive investigation of structural, microstructural, optical, electrocaloric, and energy storage properties of Ho-modified NBT-BT lead-free ceramics was conducted from room temperature to a high-temperature region. Rietveld refinement confirms the coexistence of dual-phase monoclinic (Cc) and tetragonal (P4mm) phases in Ho-modified NBT-BT ceramics. A prominent monoclinic distortion was found with increasing Ho composition up to x=0.02, and then an abrupt decrease for x=0.03 ceramic was noticed. Of particular importance is the composition of x = 0.02, which exhibits a high electrocaloric temperature change (ΔT) of 0.73 K @ E = 20 kV/cm at a temperature of 373 K, and an optimal high recoverable energy storage density (Wrec) of 1.8846 J/cm3 along with an efficiency 83% was achieved. The frequency dependence ac-conductivity study promotes the reduction of oxygen vacancies at room temperature and the dominance of single ionized oxygen vacancies at very high temperatures well above 300 °C. A small considerable increase in the energy bandgap values with the Ho3+ ion substitution in NBT-BT was observed. Under the excitation of 532 nm light, the two most prominent red fluorescence emission peaks were emitted, where the first emission band with weak intensity was observed at 657 nm which corresponds to the 5F5 → 5I8 transition, and a strong 2nd peak at 756 nm corresponds to the 5F4/5S2 →5I7 level transition of the Ho3+ ion. These findings provide a feasible multifunctional property in the applications of power electronic devices with lead-free NBT-BT ceramics via rare-earth substitution. © 202
Magnetoelectric and Multiferroic Studies on Bi<sub>0.5</sub>Ba<sub>0.5</sub>FeO<sub>3</sub> Ceramics
No full textObservation of dielectric anomalies at magnetic phase transitions in 0.5(BiFeO3)0.5(Ba0.9Sr0.1TiO3) multiferroic ceramic
No full textБИОТЕХНОЛОГИЧЕСКИЕ ПРИЕМЫ В СЕЛЕКЦИИ ОВОЩНЫХ КУЛЬТУР
No full textThe biotechnological methods of plant cell culture in vitro are represented in the article. Recent developments in the field of clonal micropropagation, androgenesis, gynogenesis, and genetic transformation of vegetable crops are shown. Importance of utilization of biotechnological approaches for successful development of agriculture is underlined.Обзор посвящен биотехнологическим методам и подходам и их использованию в селекции овощных культур. Последние достижения в области клонального микроразмножения, андрогенеза, гиногенеза и генетической трансформации овощных культур представлены в статье. Подчеркивается важность использования технологии культуры клеток in vitro для успешного развития сельского хозяйства
КУЛЬТУРНЫЙ БАКЛАЖАН - ПРОИСХОЖДЕНИЕ, ЗАДАЧИ СЕЛЕКЦИИ И ГЕНЕТИЧЕСКИЕ ИСТОЧНИКИ
No full textВ приведенном обзоре литературы представлены основные задачи и проблемы селекции баклажана и некоторые пути их решени
