The dielectric relaxation behaviors of CaCu3Ti4O12 ceramics were evaluated together with the mixed-valence structure, and formation mechanism a giant constant step was discussed. bounded by two relaxations in low high temperature ranges. low-temperature intrinsic, it very similar to electronic ferroelectricity, while relaxorlike peak assigned be result defect ordering since could suppressed O2 annealing. Both thermal activated process following Arrhenius law. Moreover, supposed that resulted...

Zn‐substituted CaCu 3 Ti 4 O 12 ceramics were synthesized by solid‐state sintering. Their microstructures and dielectric properties investigated. Ca(Cu 1− x Zn ) single‐phase structures obtained up to =0.1, the Cu + /Cu 2+ 3+ /Ti 4+ mixed‐valent structure was enhanced with increasing substitution. The giant response significantly constant increased , a plateau as high ∼9 × 10 achieved for =0.1 at kHz, while that =0 ∼3 . profoundly concerned modified structure.

Abstract CaTiO 3 is a typical linear dielectric material with high constant, low loss, and resistivity, which expected as promising candidate for the energy storage density applications. In previous work, an of 1.5 J/cm was obtained in ceramics, where strength only 435 kV/cm. fact, intrinsic predicted 4.2 MV/cm. Therefore, it should be challenge issue to enhance ceramics by optimizing microstructures. present dense fine uniform microstructures are prepared spark plasma sintering, greatly...

The magnetic, dielectric, and magnetodielectric properties of La 2 CoMnO 6 ceramics were evaluated together with the polarization‐electric field hysteresis loops. phase segregation consisting ordered disordered regions was determined in present ceramics. ordering Co 2+ Mn 4+ gave rise to ferromagnetic transition temperature as high 210 K, while disordering 3+ resulted low 80 150 K. relaxor‐like behavior combined a giant dielectric constant (∼10 5 ) ceramics, which attributed charge . Owing...

BiFeO 3 multiferroic ceramics were modified by introducing CaTiO . The stability of perovskite was increased the present modification, and single‐phase ( Bi 1 − x Ca )( Fe Ti ) O solid solutions obtained when ≥ 0.15, where symmetry changed from R c ≤ 0.2) to Pbnm 0.3). ferroelectric property enhanced because reduction leakage current increase resistivity. dielectric constant, decreased loss, remnant magnetization M r also obtained. best combination characteristics achieved at = 0.2.

Improvement of electrocaloric effect was investigated in the lead‐free undoped and Mn ‐doped Ba 0.65 Sr 0.35 TiO 3 ceramics prepared by spark plasma sintering process. Owing to merit process, a fully dense with fine grain sizes could be obtained. The ( EC ) can significantly enhanced from 0.83 K for conventional sintered 3.08 plasma‐sintered since dielectric strength dramatically increased. This work indicated an effective way achieve system at room temperature.

The structure and microwave dielectric properties of SrLaAl_1−x(Zn_0.5Ti_0.5)_xO₄ceramics were determined in the composition range of<italic>x</italic>= 0–0.9.

Electrostatic capacitors with high charge/discharge speed and long cycle lifetime play an essential role in advanced electronic electrical power systems.

The hybrid improper ferroelectricity (HIF) has been proposed as a promising way to create multiferroic materials with strong magnetoelectric coupling by the first-principle calculation, and experimental evidences of HIF in Ruddlesden-Poper Ca3(Ti1−xMnx)2O7 (x = 0, 0.05, 0.1, 0.15) ceramics have shown present work. room temperature ferroelectric hysteresis loops are observed these ceramics, polar orthorhombic structure two oxygen tilting modes confirmed X-ray powder diffraction. A first-order...

After decades of study, BiFeO 3 is still the most promising single‐phase multiferroic material due to its large polarization and high operating temperature, drawing much attention. As a typical type‐I material, magnetoelectric coupling in deemed be weak different origins ferroelectricity magnetism. Here, effect bulk readdressed both theoretically experimentally. Based on Dzyaloshinsky–Moriya interaction scenario, actually strong, with energy about 1.25 meV magnetism‐coupled parasitic...

Ba(Ti0.25Zr0.25Hf0.25Sn0.25)O3 high-entropy ceramics were prepared by a standard solid state reaction process, and the dielectric ferroelectric characteristics investigated together with structures. Both X-ray diffraction (XRD) energy dispersive spectroscopy (EDS) analysis demonstrated single-phase perovskite structure in present ceramics. A broad peak strong frequency dispersion feature was determined, which indicated typical relaxor nature originating from nanoscale domain These resulted...

MgAl 2 O 4 microwave dielectric ceramics were modified by Zn substitution for Mg, and their characteristics evaluated, along with structures. Dense (Mg 1− x )Al obtained sintering at 1550°–1650°C in air 3 h, the solid solution was determined entire composition range. With constant ɛ of just varied from 7.90 to 8.56, while Q × f value had significantly improved up a maximal 106 000 GHz =1.0. Moreover, τ declined −73 −63 ppm/°C.

The crystal structure refinement and infrared reflectivity study were carried out for SrRAlO4 (R = Sm, Nd, La) ceramics with K2NiF4 to investigate the correlations between structure, polar-phonon mode parameters, microwave dielectric properties. Fourier transform spectra in range of 50−4000 cm−1 measured evaluated by means classical oscillator fit. data extrapolated below frequency estimate intrinsic losses. Heavy distortions (Sr,R)O9 dodecahedra AlO6 octahedra are observed they should...

A comprehensive review on the latest development of ferroelectric transition and low‐temperature dielectric relaxations filled tungsten bronze ceramics are presented together with some new issues. In M 6− p R Ti 2+ Nb 8− O 30 ( = 1, 2; Ba or Sr; rare earth Bi), a is generally indicated up to three relaxations. The determined as 4/mmm → 4 mm, deeply concerned structure modulations due order/disorder ions in 1 2 sites, their random cross occupancy, B‐site ions. Both dominated by composition...

Synergic modification of BaTiO3 ceramics was investigated by Ca-substitution, and the superior dielectric ferroelectric properties were determined together with structure evolution. X-ray diffraction (XRD) analysis demonstrated a large solubility limit above x = 0.25 in Ba1−xCaxTiO3 solid solution where fine grain observed increasing x. Room temperature constant as high 1655 achieved present significantly reduced loss 0.013 (x 0.20 at 100 kHz), Curie kept almost while other two transition...

A new<italic>n</italic>= 2 type Ruddlesden–Popper compound Sr₂LaAlTiO₇was synthesized and characterized, the microwave dielectric properties were investigated together with their microstructures.

NaCl ceramics were prepared by room-temperature cold sintering using moistened powder with 4 wt% water and dry pressing dehydrated powder. When the applied uniaxial pressure is low, relative density of dry-pressed ceramic significantly lower than that cold-sintered ceramic, while former 98.5%-99.3% much higher latter (94.3%-94.6%) for high 200-300 MPa. The pressure-induced plastic deformation dominates densification also plays a role during as well dissolution-precipitation process. under...

We consider orthoferrite and orthochromite perovskites with the formula $\mathit{RM}{\mathrm{O}}_{3}$, where $R$ is a lanthanide $M$ Fe or Cr. identify an atomistic interaction that couples magnetic moments of cations oxygen octahedral rotations characterizing these crystals. show this results in effective field acting on atoms, which turn explains several intriguing features compounds, such as existence (or absence) net magnetization associated sublattice its crystallographic direction....

With the rapid development of mobile communication technology towards 5G and 6G, microwave dielectric materials with ultra-low permittivity ultra-high Qf value are urgently demanded. Here, excellent properties reported in H3BO3 ceramics molecular crystal structure, whose (2.84) density (1.46 g/cm3) record-low among low-loss ceramics. The 146,000 GHz (or loss 1.03 × 10−4 at 15 GHz) is also distinguished. Besides, can be densified room temperature by a simple cold sintering process short time...

Modification of BiFeO3 multiferroic ceramics were investigated by introducing NaNbO3 to form (Bi1−xNax)(Fe1−xNbx)O3 (x=0.1, 0.3, and 0.5) solid solutions. With increasing content, the crystalline structure changed ferroelectric properties improved. The significantly reduced leakage resulted in more regular hysteresis loop for all compositions. Dielectric characteristics evaluated. Two dielectric relaxations observed temperature ranges 550–600 650–710 K (Bi0.9Na0.1)(Fe0.9Nb0.1)O3 ceramics,...