Doping Range Research Articles

Side by Side Alignment of Donors Enabling High‐Efficiency TADF OLEDs with Insensitivity to Doping Concentration

AbstractDoping sensitivity is a great obstacle in boosting thermally activated delayed fluorescence (TADF)‐based organic light‐emitting diodes into practical application. Herein, a “side by side” donor alignment strategy is proposed to achieve decent electroluminescence performance under high doping concentration by studying the structure–property relationship of two emitters D2T‐TRZ and D2Y‐TRZ. D2T‐TRZ containing parallel aligned donors shows high photoluminescent quantum yield (PLQY) and short delayed lifetime (τd) in both doped and neat films, which endow its excellent performances with maximum external quantum efficiencies (EQEmaxs) higher than 22% under wide doping range of 10–70 wt%. While, composed of antiparallel acridans, D2Y‐TRZ presents good PLQY and relatively long τd when diluted in host matrix, but undergoes severe quenching in neat films. Consequently, D2Y‐TRZ achieves lower EQEmaxs of 14.9–16.4% within narrow range of 10–40 wt%. This result reveals parallel aligned donors as a better choice to design TADF emitters inert to doping concentration.

Site occupation and fluorescence properties of MgAl2O4: Eu3+ phosphors

A series of Mg1-xEuxAl2O4 and MgAl2-xEuxO4 (x = 0.01, 0.02, 0.03, 0.04, 0.05) phosphors were synthesized by using a low-temperature hydrothermal method combined with a calcination process. The crystal structure, morphology and fluorescence performance of the samples was investigated. Eu3+ substitutes into the majority of Mg2+ sites in the Mg1-xEuxAl2O4 and MgAl2-xEuxO4 system host lattices and does not alter the phase prototype. However, the charge balance for the two systems is maintained by vacancy generation and cation inversion. The sample morphologies are composed of platelet-like and rod-like structures with good dispersion achieved by using urea as a precipitant. The main emission peaks for all samples are located at 592 nm and 616 nm and change regularly with increasing Eu3+ concentration. Compared with the Mg1-xEuxAl2O4 series and other reported MgAl2O4: Eu3+ phosphors, the MgAl2-xEuxO4 series is prone to avoid concentration quenching in the Eu3+ doping range of x ≤ 0.05. This is attributed to the special charge balance mechanism and larger transition probability at the 5D0→7F2 level for these series of samples. The energy transfer rate among Eu3+ in the two systems is influenced differently by vacancy generation and cation inversion. The MgAl2-xEuxO4 series, as promising phosphors, shows better emission colour quality. The CIE coordinate (x, y), CCT, and colour purity for the MgAl1.95Eu0.05O4 phosphor were determined to be (0.6296, 0.3699), 2014 K, and 85.36%, respectively.

Anomalously strong near-neighbor attraction in doped 1D cuprate chains.

In the cuprates, one-dimensional (1D) chain compounds provide a distinctive opportunity to understand the microscopic physics, owing to the availability of reliable theories. However, progress has been limited by the challenge of controllably doping these materials. We report the synthesis and spectroscopic analysis of the 1D cuprate Ba2-xSrxCuO3+δ over a wide range of hole doping. Our angle-resolved photoemission experiments reveal the doping evolution of the holon and spinon branches. We identify a prominent folding branch whose intensity fails to match predictions of the simple Hubbard model. An additional strong near-neighbor attraction, which may arise from coupling to phonons, quantitatively explains experiments for all accessible doping levels. Considering structural and quantum chemistry similarities among cuprates, this attraction may play a similarly important role in high-temperature cuprate superconductors.

Understanding the ferromagnetic insulating state in Cr-doped VO2 : Density functional and tight binding calculations

Experimentally Cr doping in the rutile phase of VO$_2$ is found to stabilize a charge ordered ferromagnetic insulating state in the doping range of 10\% to 20\%. In this work, we investigated its origin at 12.5\% Cr doping using a combination of ab-initio electronic structure calculations as well as microscopic modeling. Our calculations are found to reproduce the ferromagnetic insulating state as well as a charge ordering at the V and Cr sites. The mapping of the ab-initio band structure onto a tight-binding Hamiltonian allows one to calculate the energy gain from different exchange pathways. This gain is quantified in this work for the first time and the role of charge ordering in stabilizing a ferromagnetic insulating state is understood.

Hydrogenation of Boron Carbon Nitride Thin Films for Low-k Dielectric Applications

The influence of hydrogenation on boron carbon nitride (BCN) thin films was investigated for low-k dielectric applications. The BCN thin films were deposited using radio-frequency magnetron sputtering in hydrogen, nitrogen, and argon ambiance. The hydrogen/nitrogen reactive gas flow was varied from 0/10 to 10/10 to achieve a varying range of hydrogen doping. Elemental composition and chemical bonding studies of the films were analyzed by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). XPS results confirmed the formation of B-C-N atomic hybridization, and FTIR confirmed the hydrogen doping by evidence of C–H bonds. Metal insulator metal structures were fabricated using Al and BCN thin films to measure electrical properties such as dielectric constant and resistivity. Hydrogenation of BCN caused a 68% decrease in the k value from 6.2 to 2 due to the formation of non-polar bonds. The k value of 2 reported in this study is the lowest value achieved for hydrogenated BCN films deposited by the RF magnetron sputtering technique.

Tunable magnetization reversal and exchange bias in NiCr2O4 ceramics doped with non-magnetic ions

The magnetization reversal and exchange bias (EB) effects were systematically investigated for nanocrystalline samples of NiCr2-xGaxO4 (x = 0–1.0). The intrinsic temperature-induced magnetization reversal (TIMR) effect could be modulated by doping with Ga ions and controlling the particle size. The TIMR effect was closely related to the Griffiths phase observed in this system. Both the zero-field-cooling and field-cooling EB effects could be observed simultaneously within the doping range x = 0.1–0.5. Upon doping with non-magnetic ions, the magnetic interactions of Ni–Cr and Cr–Cr were significantly diluted, which were further confirmed by specific heat measurements. Overall, the results highlight the potential to control the TIMR and EB phenomena by doping and controlling the particle size.

Raising Dielectric Permittivity Mitigates Dopant-Induced Disorder in Conjugated Polymers.

Conjugated polymers need to be doped to increase charge carrier density and reach the electrical conductivity necessary for electronic and energy applications. While doping increases carrier density, Coulomb interactions between the dopant molecules and the localized carriers are poorly screened, causing broadening and a heavy tail in the electronic density‐of‐states (DOS). The authors examine the effects of dopant‐induced disorder on two complimentary charge transport properties of semiconducting polymers, the Seebeck coefficient and electrical conductivity, and demonstrate a way to mitigate them. Their simulations, based on a modified Gaussian disorder model with Miller‐Abrahams hopping rates, show that dopant‐induced broadening of the DOS negatively impacts the Seebeck coefficient versus electrical conductivity trade‐off curve. Increasing the dielectric permittivity of the polymer mitigates dopant‐carrier Coulomb interactions and improves charge transport, evidenced by simultaneous increases in conductivity and the Seebeck coefficient. They verified this increase experimentally in iodine‐doped P3HT and P3HT blended with barium titanate (BaTiO3) nanoparticles. The addition of 2% w/w BaTiO3 nanoparticles increased conductivity and Seebeck across a broad range of doping, resulting in a fourfold increase in power factor. Thus, these results show a promising path forward to reduce the dopant‐charge carrier Coulomb interactions and mitigate their adverse impact on charge transport.

Ce-Site Dilution in the Ferromagnetic Kondo Lattice CeRh6Ge4 Supported by the National Natural Science Foundation of China (Grant Nos. 12034017 and 11974306), the National Key R&D Program of China (Grant Nos. 2017YFA0303100 and 2016YFA0300202), and the Key R&D Program of Zhejiang Province, China (Grant No. 2021C01002).

The heavy fermion ferromagnet CeRh6Ge4 is the first example of a clean stoichiometric system where the ferromagnetic transition can be continuously suppressed by hydrostatic pressure to a quantum critical point. In order to reveal the outcome when the magnetic lattice of CeRh6Ge4 is diluted with non-magnetic atoms, this study reports comprehensive measurements of the physical properties of both single crystal and polycrystalline samples of La x Ce1–x Rh6Ge4. With increasing x, the Curie temperature decreases, and no transition is observed for x > 0.25, while the system evolves from exhibiting coherent Kondo lattice behaviors at low x to the Kondo impurity scenario at large x. Moreover, non-Fermi liquid behavior is observed over a wide doping range, which agrees well with the disordered Kondo model for 0.52 ≤ x ≤ 0.66, while strange metal behavior is revealed in the vicinity of x c = 0.26.

Excess-iron driven spin glass phase in Fe1 + y Te1 – x Se x * *The work at Beijing Normal University is supported by the National Natural Science Foundation of China (Grant Nos. 11734002 and 11922402, X.L.). Work at Rice is supported by the US Department of Energy (DOE), Basic Energy Sciences (BES), under Contract No. DE-SC0012311 (P.D.). A portion

The iron-chalcogenide superconductor FeTe1–x Se x displays a variety of exotic features distinct from iron pnictides. Although much effort has been devoted to understanding the interplay between magnetism and superconductivity near x = 0.5, the existence of a spin glass phase with short-range magnetic order in the doping range (x ∼ 0.1–0.3) has rarely been studied. Here, we use DC/AC magnetization and (quasi) elastic neutron scattering to confirm the spin-glass nature of the short-range magnetic order in a Fe1.07Te0.8Se0.2 sample. The AC-frequency dependent spin-freezing temperature T f generates a frequency sensitivity ΔT f(ω)/[T f(ω)Δlog10 ω] ≈ 0.028 and the description of the critical slowing down with τ = τ 0(T f/T SG – 1)−z v gives T SG ≈ 22 K and zv ≈ 10, comparable to that of a classical spin-glass system. We have also extended the frequency-dependent T f to the smaller time scale using energy-resolution-dependent neutron diffraction measurements, in which the T N of the short-range magnetic order increases systematically with increasing energy resolution. By removing the excess iron through annealing in oxygen, the spin-freezing behavior disappears, and bulk superconductivity is realized. Thus, the excess Fe is the driving force for the formation of the spin-glass phase detrimental to bulk superconductivity.

Suppression of thermal conductivity and electronic correlations in Fe1−xRuxSb2 (0 ≤x≤ 0.6)

We present simultaneous suppression of FeSb2 thermal conductivity and electronic correlations in Fe1−xRuxSb2 (0 ≤x≤ 0.6) single crystal alloys. Small energy gap Δ1 in Kondo-insulator-like semiconductor FeSb2 associated with impurity in-gap state increases whereas the intrinsic bandgap Δ2 decreases upon Ru substitution on Fe atomic site. Thermopower is suppressed along with the intrinsic bandgap and with the thermal conductivity. The more delocalized 4d character of atomic orbital of Ru brings suppression of electronic correlations, but also an increase in impurity density which reduces phonon mean free path and surface scattering length. Our results indicate a range of Ru doping x where nanostructuring could be used to suppress thermal conductivity further, potentially toward the amorphous limit.

Complex electrical impedance and modulus characterizations of ZnO:Sn thin films in a wide temperature range

In this study, pure zinc oxide (ZnO) and tin-doped zinc oxide (Zn1−xSnxO) thin films were synthesized using successive ionic layer adsorption and reaction (SILAR) method in 40 cycles with doping ratios x = 0.05, 0.10, 0.15, and 0.20. Subsequently, structural, optical, and electrical characteristics of all synthesized thin films were properly investigated by the appropriate techniques. For structural characterizations, X-ray diffraction (XRD) technique was employed, and the data demonstrated the appropriate hexagonal wurtzite structure of the synthesized thin films and predicted the decrease of crystallite size with Sn doping. Likewise, optical characterizations were carried out through ultraviolet–visible (UV–Vis) technique, and the data showed good transparency of ZnO thin film and confirmed the increase in transparency and bandgap upon Sn doping. Additionally, to probe the electrical aspects of the synthesized thin films, impedance, modulus, and conductivity analyses were carried out as a function of frequency in a wide temperature range (450–750 K). The results demonstrated the critical effect of temperature and Sn doping ratio in ZnO thin films. At high enough temperatures, inductive effects became evident in the low-frequency region of all the thin films. And at all temperatures, 5 wt%- and 10 wt%-doped films exhibited extreme responses in the investigated doping range, where the former and the latter showed, respectively, highest and lowest conductivity as well as lowest and highest possibility of grain effects in the film structure. This behavior was confirmed using two different analysis techniques with two separate data sets, (Z, θ) and (C, G).

Manipulation of the Electronic State of Mott Iridate Superlattice through Protonation Induced Electron‐Filling

AbstractSpin‐orbit‐coupled Mott iridates show great similarity with parent compounds of superconducting cuprates, attracting extensive research interest especially for their electron‐doped states. However, previous experiments have been largely limited within a small doping range due to the absence of effective dopants, and therefore the electron‐doped phase diagram remains elusive. Here, an ionic‐liquid‐gating‐induced protonation method is utilized to achieve electron‐doping into a 5d Mott‐insulator built with a SrIrO3/SrTiO3 superlattice (SL), and a systematic mapping of its electron‐doped phase diagram is achieved with the evolution of the iridium valence state from 4+ to 3+, equivalent to doping of one electron per iridium ion. Along increasing doping level, the parent Mott‐insulator is first turned into a localized metallic state with gradually suppressed magnetic ordering, and then further evolves into a nonmagnetic band insulating state. This work forms an important step forward for the study of electron‐doped Mott iridate systems, and the strategy of manipulating the band filling in an artificially designed SL structure can be readily extended into other systems with more exotic states to explore.

Thermopower across the phase diagram of the cuprate La1.6−xNd0.4SrxCuO4 : Signatures of the pseudogap and charge density wave phases

The Seebeck coefficient (thermopower) $S$ of the cuprate superconductor La$_{1.6-x}$Nd$_{0.4}$Sr$_x$CuO$_4$ was measured across its doping phase diagram (from $p = 0.12$ to $p = 0.25$), at various temperatures down to $T \simeq 2$ K, in the normal state accessed by suppressing superconductivity with a magnetic field up to $H = 37.5$ T. The magnitude of $S/T$ in the $T=0$ limit is found to suddenly increase, by a factor $\simeq 5$, when the doping is reduced below $p^{\star} = 0.23$, the critical doping for the onset of the pseudogap phase. This confirms that the pseudogap phase causes a large reduction of the carrier density $n$, consistent with a drop from $n = 1 + p$ above $p^{\star}$ to $n = p$ below $p^{\star}$, as previously inferred from measurements of the Hall coefficient, resistivity and thermal conductivity. When the doping is reduced below $p = 0.19$, a qualitative change is observed whereby $S/T$ decreases as $T \to 0$, eventually to reach negative values at $T=0$. In prior work on other cuprates, negative values of $S/T$ at $T \to 0$ were shown to result from a reconstruction of the Fermi surface caused by charge-density-wave (CDW) order. We therefore identify $p_{\rm CDW} \simeq 0.19$ as the critical doping beyond which there is no CDW-induced Fermi surface reconstruction. The fact that $p_{\rm CDW}$ is well separated from $p^{\star}$ reveals that there is a doping range below $p^{\star}$ where the transport signatures of the pseudogap phase are unaffected by CDW correlations, as previously found in YBa$_2$Cu$_3$O$_y$ and La$_{2-x}$Sr$_x$CuO$_4$.

Analytical Design and Experimental Verification of Lateral Superjunction Based on Global Region Normalization Method

The global region normalization (GRN) method is proposed to optimize the lateral superjunction (SJ), in this article. The GRN features normalizations in the global doping range of the SJ from zero to the maximum doping concentration N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> that was theoretically determined by the pillar width W <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SJ</sub> . Then the optimization covers all the possible design points of the SJ. For the SJ with given W <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SJ</sub> and pillar length L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SJ</sub> , the specific ON-resistance R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on,sp</sub> and breakdown voltage V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B</sub> are normalized in the global region of the doping concentration N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SJ</sub> . With the GRN method, the global normalization function f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">η</sub> is deduced to reflect the quantitative variation trend of R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on,sp</sub> - V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B</sub> and a design formula of the optimized N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SJ</sub> is presented. Furthermore, lateral SJ devices were fabricated according to the formula. The measured R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on,sp</sub> values of the SJ devices are reduced by almost 35% when compared with the theoretical limit of the triple RESURF device in a voltage range of 100-400 V. The experiments also reveal that the measured net R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on,sp</sub> of the SJ region approaches the R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on.sp</sub> ∝ V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B</sub> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1.03</sup> relationship.

Stripe phases in WSe2/WS2 moiré superlattices.

Stripe phases, in which the rotational symmetry of charge density is spontaneously broken, occur in many strongly correlated systems with competing interactions1-11. However, identifying and studying such stripe phases remains challenging. Here we uncover stripe phases in WSe2/WS2 moiré superlattices by combining optical anisotropy and electronic compressibility measurements. We find strong electronic anisotropy over a large doping range peaked at 1/2 filling of the moiré superlattice. The 1/2 state is incompressible and assigned to an insulating stripe crystal phase. Wide-field imaging reveals domain configurations with a preferential alignment along the high-symmetry axes of the moiré superlattice. Away from 1/2 filling, we observe additional stripe crystals at commensurate filling 1/4, 2/5 and 3/5, and compressible electronic liquid crystal states at incommensurate fillings. Our results demonstrate that two-dimensional semiconductor moiré superlattices are a highly tunable platform from which to study the stripe phases and their interplay with other symmetry breaking ground states.

Mid-wave to near-IR optoelectronic properties and epsilon-near-zero behavior in indium-doped cadmium oxide

Indium-doped cadmium oxide (In:CdO) thin films exhibit tunable epsilon-near-zero (ENZ) modal frequencies across a wide spectral range, bridging the mid-wave and near-infrared (IR). In:CdO thin films are prepared by reactive cosputtering from metallic Cd and In targets using high-power impulse magnetron sputtering (HiPIMS) and radio frequency sputtering, respectively. Using this approach, CdO thin films with carrier concentrations ranging from $2.3\ifmmode\times\else\texttimes\fi{}{10}^{19}$ to $4.0\ifmmode\times\else\texttimes\fi{}{10}^{20}\phantom{\rule{0.16em}{0ex}}\mathrm{c}{\mathrm{m}}^{\text{--}3}$ and mobilities ranging from 300 to $400\phantom{\rule{0.16em}{0ex}}\mathrm{c}{\mathrm{m}}^{2}/\mathrm{V}\phantom{\rule{0.16em}{0ex}}\mathrm{s}$ are readily achieved. UV-VIS absorption spectra are used to measure optical bandgap, revealing a Burstein-Moss shift of 0.58 eV across the doping range investigated. Optical measurements demonstrate the tunability of near-perfect plasmonic ENZ absorption across the mid-wave and into the near-IR spectral ranges by controlling the carrier concentration through doping, while tuning the film thickness for impedance matching. In comparison to other dopants that can be introduced to HiPIMS-deposited CdO, In offers the largest range of carrier concentrations while maintaining high mobility, thus allowing for the widest accessibility of the IR spectrum of a single plasmonic material grown by sputtering.

Thermoelectric Properties of Cobalt-Doped β-FeSi2 with SiC Nanoparticle Inclusions

Cobalt doping is an effective approach to improve the thermoelectric properties of semiconducting β-FeSi2 materials. Through preparing β-Fe1−xCoxSi2 samples with x ranging from 0.05 to 0.11, an enhanced ZT of about 0.35 could be achieved within quite a wide doping range (8 mol.% to 10 mol.%) at around 950 K. To further improve the thermoelectric performance, a composite structure consisting of a large grain matrix of β-Fe0.92Co0.08Si2 and inert SiC nanoparticle inclusions was intentionally employed to reduce the lattice thermal conductivity. The microstructure and the effects on the thermoelectric properties of β-Fe0.92Co0.08Si2 with various SiC nanoparticle concentrations were explored. The SiC nanoparticles could be well dispersed into the matrix material without significant agglomerations by the powder processing method. However, the thermal conductivity was not considerably reduced while the electrical properties were affected to some extent, resulting in no gain in the ZT. The current results show that it is feasible to prepare high-quality nanocomposites through the powder processing method, and enhanced thermoelectric performance is expected when using other chemically stable inclusions with lower thermal conductivity and smaller size.

Reduced Hall carrier density in the overdoped strange metal regime of cuprate superconductors

Efforts to understand the microscopic origin of superconductivity in the cuprates are dependent on knowledge of the normal state. The Hall number in the low-temperature, high-field limit nH(0) has a particular importance because, within conventional transport theory, it is simply related to the number of charge carriers, so its evolution with doping gives crucial information about the nature of the charge transport. Here we report a study of the high-field Hall coefficient of the single-layer cuprates Tl2Ba2CuO6+δ (Tl2201) and (Pb/La)-doped Bi2Sr2CuO6+δ (Bi2201), which shows how nH(0) evolves in the overdoped—so-called strange metal—regime of cuprates. We find that nH(0) increases smoothly from p to 1 + p, where p is the number of holes doped into the parent insulating state, over a wide range of doping. The evolution of nH correlates with the emergence of the anomalous linear-in-temperature term in the low-temperature in-plane resistivity. The results could suggest that quasiparticle decoherence extends to dopings well beyond the pseudogap regime. A study of the high-field Hall coefficient in thallium- and bismuth-based single-layer cuprates demonstrates a smooth evolution of this quantity from p to 1 + p over a wide doping range.

Anomalous normal-state magnetotransport in an electron-doped cuprate

We report magnetoresistance and Hall angle measurements of the electron-doped cuprate La$_{2-x}$Ce$_x$CuO$_4$ over a wide range of dopings from $x = 0.08 - 0.17$. Above 100 K, we find an unconventional $\sim H^{3/2}$ magnetic field dependence of the magnetoresistance observed in all samples doped within the superconducting dome. Further, the measured magnetoresistance violates Kohler's rule. Given the ubiquity of this anomalous magnetoresistance at high temperatures above the superconducting dome, we speculate that the origin of this behavior is linked to the unusual $\rho \sim T^2$ resistivity observed over the same wide parameter range at high temperatures. We also find a strong doping dependence of the Hall angle with an unconventional temperature dependence of $\cot \theta_H \sim T^{4}$ ($T^{2.5}$) for samples doped below (above) the Fermi surface reconstruction doping $x_{\text{FSR}} = 0.14$.

Comparing the electromechanical properties of CaTiO3‐ and BaZrO3‐modified Bi0.5Na0.5TiO3–SrTiO3 ceramics

The effects of CaTiO3 (CT) and BaZrO3 (BZ) modification upon the crystal structure and electromechanical properties of lead‐free Bi0.5Na0.5TiO3–SrTiO3 piezoelectric ceramics were compared within a doping range of 0–4 mol%. The different effects of CT and BZ modification upon the phase transition are clearly observed in the polarization and strain hysteresis loops. The CT‐modified specimens maintain strong ferroelectricity without any abnormal enhancement in the electric field‐induced strain. However, the addition of as little as 1 mol% BZ induces a transition from a nonergodic relaxor phase to an ergodic relaxor phase, thus resulting in disruption of the ferroelectric order and the generation of a high field‐induced strain. The present authors believe that the substitution of large ions (such as Zr4+) into the B‐sites, rather than the A‐sites, of the Bi0.5Na0.5TiO3‐based ceramics plays a significant role in the phase transition behavior.