Dielectric Anomaly Research Articles

Shock waves impulses assisted hydrothermal method of synthesizing of organic 12-B polyanions and its applications

To alleviate the problem, a new and unique property for the complex is desirable. Novel hexagonal stratified structures have been observed. This category of hybrid material is prepared with surfactant, polyoxometalate and s-triazine complex through ionic interaction. To know the tenacity of the present study for an inventive property was further studied. A novel technique of shock wave impulsed material was developed in this work; employed to fabricate the FO TFN membrane. The experimental results recommended that notable attention should be paid to the 0.1 wt % POM-AG incorporated TFN membrane which exhibits 9.2 LMH higher pure water flux compared to the composite membranes without shock imposed material incorporation that were synthesized. Those water enhancements of FO membranes could be assigned the presence of the POM-AG, which is allocated evenly throughout the PA active layer. Thus, the formation of porous selective layer is minimized water transport resistance. The dielectric and conduction mechanisms were monitored through dielectric anomalies and intramolecular charge transfer of the covalence of Mo-O and NH+, manifested by dipolar relaxation. An unassociated in intensity originated from the differential of the selective orientation during the analyses of the experimental data for the powder samples. Furthermore, the structural, morphological and thermal properties of hock wave impulsed hybrid material have been investigated using XRD, SEM, FT-IR, TGA, and NMR techniques. However, the FO membrane biological activity was reported above 70%.

Conductivity measurement and dielectric, impedance and modulus spectroscopic studies on bis (P-nitrophenol) melaminium monohydrate

The present work is aimed to study the dielectric and electrical characteristics of bis (P-nitrophenol) melaminium monohydrate (BNPM) over the temperature and frequency ranges of 333–453 K and 50 Hz–5 MHz, respectively. The dielectric properties such as dielectric constant (ε′), dielectric loss (ε″), ac-conductivity (σac), real (M′) and imaginary part (M″) of dielectric modulus were investigated as a function of temperature and frequency. The impedance analysis has been carried out using Cole-Cole plots to elucidate the electrical conduction mechanism. Further, observations indicated that the grain boundaries are more resistive and capacitive than the grains, inducing inhomogeneity in the material, which, in turn, causes broad frequency-dependent dielectric anomalies. The observed frequency-dependence of the AC conductivity validated the Jonscher power law. Further, an asymmetric dispersion peak in the imaginary part of the electrical modulus (M”) was noticed, indicating that the fabricated material exhibits non-Debye relaxation behavior.

Dielectric Relaxation and Dielectric Switching Behaviors in (N,N-Diisopropylethylamine) Tetrachloroantimonate(III).

Dielectric switches have drawn renewed attention to the study of their many potential applications with the adjustable switch temperatures (Ts ). Herein, a novel antimony-based halide semiconductor, (N,N-diisopropylethylamine) tetrachloroantimonate ((DIPEA)SbCl4 , DIPEA+ =N,N-diisopropylethylamine), with dielectric relaxation behavior and dielectric switches has been successfully synthesized. This compound, consisting of coordinated anion chains and isolated DIPEA+ cations, undergoes an isostructural order-disorder phase transition and shows a step-like dielectric anomaly, which can function as a frequency-tuned dielectric switch with highly adjustable switch temperature (Ts ). Variable-temperature single-crystal structure analyses and first-principles molecular dynamics simulations give information about the general mechanisms of molecular dynamics. This work enriches the dielectric switch family and proves that hybrid metal halides are promising candidates for switchable physical or chemical properties.

Insights into the structural symmetry of YCrO3 from synchrotron X-ray diffraction

A high-resolution synchrotron X-ray diffraction study of a single-crystal YCrO3 compound was employed to obtain its crystallographic information, such as lattice parameters, atomic positions, bond lengths and angles, and local crystalline distortion size and mode. The measurements were taken at 120 K (below the antiferromagnetic transition temperature T N ≃ 141.5 K), 300 K (between T N and the ferroelectric transition temperature T C ≃ 473 K) and 500 K (above T C). Using the high intensity of synchrotron X-rays, it was possible to refine collected patterns with the previously proposed noncentrosymmetric monoclinic structural model (P1211, No. 4) and determine detailed structural parameters. Meanwhile, for a controlled study, the data were refined with the centrosymmetric orthorhombic space group (Pmnb, No. 62). The lattice constants a, b and c and the unit-cell volume increased nearly linearly upon heating. With the P1211 space group, the distributions of bond lengths and angles, as well as local distortion strengths, were observed to be more dispersed. This implies that (i) the local distortion mode of Cr2O6 at 120 K correlates with the formation of canted antiferromagnetic order by Cr1–Cr2 spin interactions, primarily via intermediate O3 and O4 ions; and (ii) the previously reported dielectric anomaly may have a microscopic origin in the strain-balanced Cr1—O3(O4) and Cr2—O5(O6) bonds as well as the local distortion modes of Cr1O6 and Cr2O6 octahedra at 300 K. Local crystalline distortion is shown to be an important factor in the formation of ferroelectric order. The comprehensive set of crystallographic information reported here allows for a complete understanding of the unique magnetic and ferroelectric properties of YCrO3.

Above room temperature dielectric switchable organic co-crystal [C4H4O4]⋅[C3H9N] with Hirshfeld surface analyses

A new co-crystal [C 4 H 4 O 4 ]∙[C 3 H 9 N] was synthesized, where [C 4 H 4 O 4 ]=fumaric acid and [C 3 H 9 N]= isopropylamine. A reversible phase change happened at 352/357 K and it belongs to a homogenous phase change. Hirshfeld surface analyses reveal that three interactions of H⋅⋅⋅H, H⋅⋅⋅O and H⋅⋅⋅C contribute to more than 90% the total forces. Dielectric anomalies were also observed accompanied with structural phase change. • The forces of the H⋅⋅⋅H, H⋅⋅⋅O and H⋅⋅⋅C bond interactions by Hirshfeld surface analyses are different at the high and low dielectric states. We report a new dielectric phase change co-crystal [C 4 H 4 O 4 ]⋅[C 3 H 9 N] 1 , among which [C 4 H 4 O 4 ] is fumaric acid and [C 3 H 9 N] is isopropylamine / IPA. Single-crystal X-ray measurements show space group of 1 belongs to monoclinic P 2 1 / c space group, and a homogeneous phase change occurs. Hirshfeld surface analyses reveal that three interactions of H⋅⋅⋅H, H⋅⋅⋅O and H⋅⋅⋅C contribute more than 90 % to the total forces, and the forces of the three bonds are different at different phases. \

Structural, Electrical, and Magnetic Properties of Hexagonal Lu0.5−xZrxSc0.5FeO3 Ceramics

Hexagonal Lu0.5−x Zr x Sc0.5FeO3 polycrystalline samples are synthesized by conventional solid‐state reaction. Effects of slight Zr4+ ions substitution on the structural distortion and magnetoelectric properties are investigated. The coexistence of Fe2+ and Fe3+ is checked by X‐ray photoelectron spectroscopy (XPS). X‐ray diffraction (XRD) and Raman spectrum (RS) microstructural analysis reveal that all samples are in the hexagonal structure with the polar space group of P6 3 cm. With x increasing slightly, the tilting of FeO5 bipyramids and the bending of rare‐earth atomic layers are suppressed. The Néel temperature T N of antiferromagnetic (AFM) transition is decreased, whereas the weak ferromagnetic (WFM) order is strengthened. The permittivity ε r of the samples is significantly increased. A dielectric anomaly near T N in Lu0.45Zr0.05Sc0.5FeO3 may indicate magnetoelectric coupling. It is attributed to the spin–phonon coupling as is evidenced by the Raman phonon modes. The improvement of dielectricity and magnetoelectric coupling is explained by considering the Dzyaloshinskii–Moriya interaction, structural distortion, and the incremental ratio of Fe2+ ions. These results provide an idea for sensitive control of electric and magnetic properties in related materials.

Crystal structure, dielectric properties, and optical bandgap control in KNbO3–BiMnO3 ceramics

Abstract(1 − x)KNbO3–xBiMnO3 (0 ≤ x ≤ 0.25) ceramics were prepared by the solid‐state reaction method. An X‐ray diffraction analysis combined with Raman spectroscopy showed the co‐solubility of Bi and Mn in the orthorhombic structure to be less than 5% BiMnO3. Orthorhombic and pseudocubic symmetries coexist in the 0.05 ≤ x ≤ 0.15 region, coinciding with a bimodal grain size distribution. This coexistence of crystal symmetries is further corroborated by several anomalies in the dielectric behavior, which can be ascribed to structural phase transitions. For x ≥ 0.20, only one dielectric anomaly is detected around 100°C, which is commensurate with in situ Raman spectroscopy analysis. This work also shows that Bi/Mn co‐doping can be employed to tailor the bandgap of KNbO3, which narrows continuously with increasing x, resulting in ∼1‐eV narrowing for single‐phase x = 0.25. This may offer the possibility to employ this ferroic material in photoresponsive technologies.

Magnetic ordering induced magnetodielectric effect in Ho2Cu2O5 and Yb2Cu2O5

Materials with strongly coupled magnetic and electronic degrees of freedom provide new possibilities for practical applications. In this paper, we have investigated the structure, magnetic property, and magnetodielectric (MD) effect in Ho2Cu2O5 and Yb2Cu2O5 polycrystalline samples, which possess a non-centrosymmetric polar structure with space group Pna21. In Ho2Cu2O5, Ho3+ and Cu2+ sublattices order simultaneously, exhibiting a typical paramagnetic to antiferromagnetic transition at 13.1 K. While for Yb2Cu2O5, two magnetic transitions which originate from the orderings of Yb3+ (7.8 K) and Cu2+ (13.5 K) sublattices are observed. A magnetic field induced metamagnetic transition is obtained in these two cuprates below Néel temperature (T N). By means of dielectric measurement, distinct MD effect is demonstrated by the dielectric anomaly at T N. Meanwhile, the MD effect is found to be directly related to the metamagnetic transition. Due to the specific spin configuration and different spin evolution in the magnetic field, a positive MD effect is formed in Ho2Cu2O5, and a negative one is observed in Yb2Cu2O5. The spontaneous dielectric anomaly at T N is regarded as arising from the shifts in optical phonon frequencies, and the magnetoelectric coupling is used to interpret the magnetic field induced MD effect. Moreover, an H–T phase diagram is constructed for Ho2Cu2O5 and Yb2Cu2O5 based on the results of isothermal magnetic and dielectric hysteresis loops.

Above room-temperature dielectric switching in a new Zn-halide hybrid crystal based on pyrrolidine-derivative

A new Zn-halide hybrid crystal based on pyrrolidine-derivative exhibits reversible phase transition at around 330 K/320 K (heating/cooling). • (HNBNMP) 2 (ZnCl 4 ) (HNBNMP = N-bromomethyl-N-methylpyrrolidinium cation, compound 1 ), shows a reversible phase transition at 330/320 K (heating/cooling) through differential scanning calorimetry (DSC). • Variable-temperature single-crystal structural analysis and powder X-ray diffraction patterns verify the structural phase transition. • Variable-temperature dielectric measurements show the dielectric switching behavior indicating the potential application in the dielectric functional materials. We have successfully synthesized compound 1 (HNBNMP) 2 (ZnCl 4 ) (HNBNMP = N-bromomethyl-N-methylpyrrolidinium cation) through the slow evaporation method at room temperature. Several studies (differential scanning calorimetry measurements, single crystal structural analysis, variable-temperature powder X-ray diffraction and dielectric measurements) show that compound 1 has a reversible structural phase transition at around 330 K/320 K (heating/cooling), respectively. Variable-temperature powder X-ray diffraction patterns further demonstrate that compound 1 undergoes a phase transition. Meanwhile, the unique phase transition behavior was also confirmed by its remarkable dielectric and thermal anomalies around the phase transition point. The step-like dielectric switching in compound 1 can be mainly ascribed to the motional changes of polar components between room-temperature and high-temperature phases. This finding should stimulate further synthesis for switchable functional materials.

Synthesis and characterization of new multiferroic (BiBa)(FeTi2)O8

The present communication reports the study of various properties (i.e., structural, electrical, dielectric, ferroelectric, and magnetic) of new multiferroic: (BiBa)(FeTi2)O8 synthesized by a mixed oxide reaction route. The analysis of the X-ray diffraction profile at room temperature ensures its phase formation in the orthorhombic crystal structure. The micrographic study divulges irregular shape grains (mostly rectangular) with an average grain size of 3.5 μm. The compositional study displays the desired stoichiometry. The study of electrical (impedance, modulus, and conductivity) and dielectric properties (dielectric constant and tangent loss) of the sample at different temperatures (RT – 773 K) and electric field frequency (1 kHz-1MHz) provides many new experimental data, and insight mechanisms. The temperature dependence of the dielectric constant exhibits a dielectric anomaly around 523 K that may be due to the combined effect of oxygen vacancy mediated redox reaction (Fe3+→Fe2+ and Ti4+→Ti3+) and Maxwell-Wagner polarization. The loss tangent follows a similar trend to that of the dielectric constant except for an additional low-frequency relaxation peak of about 543 K. The dielectric loss tangent exhibits low value in low temperature and high-frequency regions, indicating that the sample can be a potential candidate for data storage devices. The ferroelectric recording shows a non-linear PE loop at room temperature. The room temperature magnetic recordings show evidence of weak ferromagnetism due to suppression of spiral spin structure as opposed to the antiferromagnetic nature of BiFeO3. The coexistence of these unique features enables the synthesized sample to be used in voltage-controlled data storage devices.

High energy storage density and temperature stable dielectric properties of (1-x)Bi0.5(Na0.82K0.18)0.5Ti0.99(Y0.5Nb0.5)0.01O3-xNaNbO3 ceramics

The development of lead-free ceramics with high energy storage density is critical due to the human health and environmental hazards of lead and the demand to miniaturize and integrate electronic devices. Nevertheless, the high applied electric field limits their use in integrated circuits. In this work, (1-x) Bi0.5(Na0.82K0.18)0.5Ti0.99(Y0.5Nb0.5)0.01O3-xNaNbO3 (BNKTYN-100xNN) ceramics were prepared, and excellent energy storage properties were obtained. It has revealed that NaNbO3 dopant reduces remanent polarization and increases relaxor degree. BNKTYN-9NN ceramics has high energy storage density (Wrec =1.6 J/cm3) and responsivity (ξ = Wrec/E = 145.5 J/(kV•m2)) under 110 kV/cm. Meanwhile, good temperature stability (20–120 °C) and fatigue resistance (105 cycles) were also obtained in BNKTYN-9NN ceramics. In addition, doping NaNbO3 suppresses the dielectric anomaly peak, and BNKTYN-9NN ceramics has excellent temperature-stable dielectric permittivity from 53° to 447°C. These results suggest that BNKTYN-100xNN ceramics are promising for energy storage equipment.

Optical properties, dielectric relaxor behavior, impedance and modulus spectroscopy of 0.8BiFeO3-0.2CaTiO3 composite

0.8BiFeO3-0.2CaTiO3 (0.8BFO-0.2CTO) was synthesized by the sol-gel route. Structural characterization was performed by X-ray diffraction which confirms the rhombohedral structure. FESEM analysis reveals the irregular grains that are inhomogenous and slightly dense. Temperature-dependent dielectric permittivity shows a dielectric anomaly near the magnetic phase transition temperature (TN) of BiFeO3 as well as relaxor-type ferroelectric properties. The PE loop confirms the presence of ferroelectricity in the sample. Frequency-dependent ac conductivity exhibits low frequency dispersion and was well explained by Jonscher power law. The obtained fitting parameters A (pre-exponential factor that indicates polarizability) and n (dimensionless frequency exponent) show maxima and minima at the transition temperature. The electrical properties were further analysed by impedance and modulus spectroscopy. According to these analysis, the relaxation time was distributed and does not follow the Debye type behaviour. Nyquist plots had been used to estimate grain and grain boundary contributions. A typical negative temperature coefficient of resistance (NTCR) behaviour was apparent due to the decrement in bulk and grain boundary resistances as the temperature increases. The temperature-dependent relaxation time revealed Arrhenius's behaviour. 0.8BFO-0.2CTO exhibits absorption and shows a transmittance of 40–44% in the visible region of spectra. The obtained value of Eg was ∼2.26 eV, which implies the application in ultrafast optoelectronic devices. The good ability of absorption in visible region, high transmittance, the increase of extinction coefficient with wavelength, and low band gap makes 0.8BFO-0.2CTO an extraordinary material for optical devices application. The sample also shows a decrease in magneto-capacitance and increase in magneto-impedance which reflects the presence of strong magneto dielectric coupling in 0.8BFO-0.2CTO at room temperature.

Diffuse dielectric behaviors in non-stoichiometric sodium niobate-based ceramics via Bi-substitution

Systematic investigation on the phase transition, dielectric behavior, and ferroelectric property of non-stoichiometric sodium niobate-based antiferroelectric (AFE) ceramics is carried out via Bi-substitution. Doping Bi3+ is capable of adjusting phase transition temperature meanwhile accelerating the formation of polar nanoregions instead of the long-range order structure. The phase transition is identified by the structural Rietveld refinement from the orthorhombic P phase to the pseudo-cubic phase consisting of the P and orthorhombic R phase as Bi3+ dopant increases. The composition regulation shifts the dielectric anomaly to a lower temperature and effectively enhances the relaxor nature. Specifically, associated with the diffuse dielectric relaxation aroused by oxygen vacancy defect, excellent thermal stability is achieved in a wide temperature range from −82 °C to 408 °C. Additionally, the simultaneously significant improvement of the recoverable energy density and efficiency is gained at moderate electric fields. This work makes it an alternative AFE strategy for the application of high-temperature capacitor.

Organic–Inorganic Hybrid Compound [H2-1,5-Diazabicyclo[3.3.0]octane]ZnBr4 with Reverse Symmetry Breaking Shows a Switchable Dielectric Anomaly and Robust Second Harmonic Generation Effect

An organic-inorganic hybrid molecule [3.3.0-H2dabco]ZnBr4 (1) with switchable phase transition, dielectric anomaly, and second harmonic generation (SHG) effect was synthesized by reaction of 1,5-diazabicyclo[3.3.0]octane (3.3.0-dabco) with ZnBr2 in concentrated hydrobromic acid aqueous solution. Differential scanning calorimetry (DSC) and dielectric measurements revealed that 1 exhibits a reversible high-temperature phase transition, accompanied by a distinct step-like dielectric anomaly at 373 K. Exceptionally, the single crystal structure analysis at different temperatures revealed that 1 undergoes reverse symmetry breaking during the phase transition, in which the high-symmetry space group Cc in the low temperature phase (LTP) is transformed to the low-symmetry space group P1̅ in the high temperature phase (HTP). In addition, with the conversion from the non-centrosymmetric (NCS) to the centrosymmetric (CS) space group, the SHG of 1 can switch from SHG-ON to SHG-OFF for at least four cycles without obvious decay.

Localization of Dielectric Anomalies with Multi-Monostatic S11 Using 2D MUSIC Algorithm with Spatial Smoothing.

This article demonstrates that the complex value of S11 of an antenna, acquired in a multi-monostatic configuration, can be used for localization of a dielectric anomaly hidden inside a dielectric background medium when the antenna is placed close (~5 mm) to the geometry. It uses an Inverse Synthetic Aperture Radar (ISAR) imaging framework where data is acquired at multiple frequencies and look-angles. Initially, near-field scattering data are used for simulation to validate this methodology since the basic derivation of the Multiple Signal Classification (MUSIC) algorithm is based on the plain wave assumption. Later on, from an applications perspective, data acquisition is performed using an antipodal Vivaldi antenna that has eight constant-width slots on each arm. This antenna operates in a frequency range of 1 to 8.5 GHz and its S11 is fed to the 2D MUSIC algorithm with spatial smoothing whereas the antenna artifact and background effect are removed by subtracting the average S11 at each antenna location. Measurements reveal that this methodology gives accurate results with both homogeneous and inhomogeneous backgrounds because the size of data sub-arrays trades between the image noise and resolution, hence reducing the effect of inhomogeneity in the background. In addition to near-field ISAR imaging, this study can be used in the ongoing research on breast tumors and brain stroke detection, among others.

Magnetic, magnetodielectric, and magnetocaloric properties of new polar oxides RCrWO6 (R = Sm, Eu, Gd, and Tb)

We report new magnetic oxides RCrWO6 (R = Sm, Eu, Gd, and Tb) crystallizing in the polar orthorhombic structure (Space Group: Pna21), where edge-shared dimers of CrO6 and WO6 octahedra are connected by sharing corners and establish a three-dimensional framework. All these compounds exhibit antiferromagnetic ordering of Cr3+ spins at TN ∼ 28–32 K, except SmCrWO6, which shows weak ferromagnetism below TN = 32 K. Isothermal magnetization curves of RCrWO6 (R = Gd and Tb) at low temperatures show field-induced metamagnetic transition. Further, a dielectric anomaly at TN in all these compounds evidences the magnetodielectric effect. In addition, GdCrWO6 demonstrates magnetocaloric effect (MCE) with a maximum magnetic entropy change of 9.22 J kg−1K−1 at 70 kOe with relative cooling power (RCP) ∼ 101 J kg-1. On the other hand, TbCrWO6 exhibits both conventional and inverse magnetocaloric effects with significant entropy change and RCP.

Analysis of dielectric and electrical transport properties of NdFeAsO ceramic

The iron-based ceramic NdFeAsO was synthesized by the solid-state reaction method. The tetragonal crystal structure was confirmed at room temperature through the X-ray diffraction technique. The dielectric characteristics i.e. dielectric constant (εr) and loss tangent (tanδ) of the sample were studied at a wide range of temperature and frequencies with an impedance analyzer and revealed that these quantities decreased with an increase in frequency. The dielectric anomalies were observed in the studied sample, which was found to be shifting towards the higher temperature side on increasing the frequency. The analysis of ac conductivity data of the compound obeyed Jonscher’s universal power law as well as the Arrhenius equation. The compound showed a negative temperature coefficient of resistance (NTCR) behavior. The electrical conduction mechanism in the sample can be explained through the correlated barrier hopping (CBH) model.

C4H4O4]⋅[C6H13N] as a nonlinear optical co-crystal with spike-like dielectric anomalies

Nonlinear optical (NLO) effects have important applications in optoelectronic technology, such as frequency conversion and information processing. Here, we report a NLO co-crystal [C4H4O4]∙[C6H13N] 1, where [C4H4O4] is fumaric acid and [C6H13N] is cyclohexylamine/CHA. Second harmonic generation (SHG) intensity of compound 1 is 1.25 × KH2PO4. The variable-temperature single-crystal X-ray structural measurements reveal that compound 1 crystallizes in triclinic P1 space group accompanied with a homogeneous phase change. The structural phase change of compound 1 is mainly attributed to order-disorder transition resulted from the thermal movements of cyclohexylamine cations. Spike-like dielectric anomalies can be observed at different frequencies.

Effect of Mn-doping on the morphological and electrical properties of (Ba0·7Sr0.3) (MnxTi1−x)O3 materials for energy storage application

Lead-free (Ba0·7Sr0.3) (MnxTi1−x)O3 (x = 0.0, 1.0, 2.0, 4.0, 6.0, and 8.0%) ceramics were effectively synthesized by the sol-gel process. XRD and Raman spectroscopy confirm the single-phase perovskite structure with tetragonal symmetry, for all compositions. An in-depth analysis of the chemical composition and thermochemistry of the ceramics was carried out via FT-IR and TG-DTG. Morphological analyses of the samples revealed that doping Mn at higher concentrations suppresses the grain size and grain growth rate. The dielectric properties increased first and then decreased with increasing Mn content. The ferroelectric properties represented similar trend in polarization and energy storage efficiency as showed in dielectric properties. 2% Mn-doped sample exhibits the best dielectric and energy storage performance which is attributed to increased densification and grain size effects. Dielectric anomaly caused by defect dipole polarization was observed in temperature-dependent dielectric constant curves, for 6% and 8% Mn-doped samples. This study is helpful to establish the relationship between the structure, morphology, dielectric and ferroelectric properties of Mn substituted Ba0·7Sr0·3TiO3 ceramics.

Structural phase transition in a charge-transfer compound: tropylium hexafluoridoantimonate(V)-1,4-dimethylnaphthalene (1/1).

Molecular motion in crystals has attracted much attention for the development of stimuli-responsive materials. The most studied are molecules with few atoms or highly symmetrical molecules. To develop molecules with new motion characteristics, we synthesized a charge-transfer compound, namely, tropylium hexafluoridoantimonate(V)-1,4-dimethylnaphthalene (1/1), (C7H7)[SbF6]·C12H12, and studied its structural phase transition. In this compound, the tropylium cation and the 1,4-dimethylnaphthalene molecule have planar geometry, but the latter has low symmetry. They are stacked as a one-dimensional chain structure through π-π charge-transfer interactions. Weak intermolecular interactions and planar molecular geometry result in a large degree of freedom of in-plane motion. Upon heating, due to the in-plane rotation of the molecules, the compound undergoes an order-disorder structural phase transition (phase-transition temperature = 334 K). The space group of the room-temperature phase is P21/m and the space group of the high-temperature phase is P4/mmm. This phase transition is accompanied by significant dielectric anomalies. The current investigation shows that the structural features of the title compound can be used to construct functional materials with phase transitions, such as molecular ferroelectrics.