Glycine Phosphite Research Articles

Rapid enhancement of optical transparency on glycine phosphite crystals by shock waves

Rapid enhancement of optical transparency on glycine phosphite crystals by shock waves

Simple 4-segment thermal cycling pyroelectric measurement protocol for differentiating between ferroelectric and non-ferroelectric materials

The rare-earth chromates (RECrO$_3$) and manganites (REMnO$_3$) where, RE = Eu, Y, Dy, Ho, Gd are constantly under scrutiny in search of room temperature magnetoelectric multiferroics. However, the artefacts and undesirable signal in some of the measurements pose a severe challenge in confirming the ferroelectric (FE) phase, especially in reference to pyroelectric current measurement technique. In this regard, we propose a simple modified approach to pyroelectric current measurement named as 4-segment thermal cycling protocol. This protocol assists in isolating the elusive, irreversible thermally stimulated current from the currents associated with spontaneous and reversible nature of the electric polarization in FE phase. In order to explain working principle of the protocol, we have compared simulated response of two hypothetical materials; an FE material free of space charges and a paraelectric material possessing only space charges. Further, we experimentally verify these new protocols in a single crystal of prototype ferroelectric material, Glycine Phosphite. This report primarily focuses on detailed investigation of ferroelectricity using the proposed protocol in two polycrystalline materials, HoCrO$_3$ and DyFe$_{0.5}$Mn$_{0.5}$O$_3$ where, the former has been reported to be multiferroic earlier. Our elaborative and careful approach to pyroelectric studies expound on the absence of reversible spontaneous electric polarization at temperature ranges tested in both, HoCrO$_3$ and DyFe$_{0.5}$Mn$_{0.5}$O$_3$.

The effect of hydrostatic compression on the crystal structure of glycinium phosphite

The crystal structure of glycinium phosphite (GPI) was studied in the pressure range from ambient to 6.5 GPa at 293 K using single-crystal X-ray diffraction. The changes in the unit-cell volume and parameters were continuous and anisotropic. The major compression was observed normal to the direction of the spontaneous polarization that occurs in this structure during a ferroelectric phase transition on cooling, whereas the structural compression along the b axis coinciding with the 21 axis was almost zero. The effect of pressure on the hydrogen bonds linking the H2PO3 tetrahedra into zigzag chains along the c axis was different from that on the hydrogen bonds connecting the glycinium cations with the H2PO3 tetrahedra in the (b × c) plane. The discontinuous changes in the geometries of selected hydrogen bonds at about 1.21 GPa may be evidence of a phase transition, e.g. into an ordered ferroelectric phase (with ordered positions of protons). The anisotropy of compression of GPI in the ferroelectric state (at 0 K) was studied using DFT calculations taking into account dispersive van der Waals interactions. The calculations predicted negative linear compressibility along the b axis.

Influence of carboxylic acids on structural, optical, thermal, and electrical properties of ferroelectric glycine phosphite single crystals

Influence of carboxylic acids on structural, optical, thermal, and electrical properties of ferroelectric glycine phosphite single crystals

Influence of sodium trimetaphosphate on glycine phosphite single crystals grown by modified thermal gradient method

The unidirectional sodium trimetaphosphate doped glycine phosphite (STM-GPI) single crystals were grown by a modified thermal gradient solution (TGS) growth method. The single crystals were grown with diameters ranging from 18 to 35 mm. The intrinsic and extrinsic point defects were created due to the doping effect. The phase changes in lattice parameter values and intensity of reflections have been analysed in this study. The effect of point defects due to STM doping in glycine phosphite has been studied. The full width at half maximum (FWHM) of the high-resolution diffraction curves was confirmed as 70 arc s. The defected single crystal shows a lower laser damage threshold value. The bending and stretching vibrations were changed in functional groups. The changes on the surface of the crystal were analysed with real-time growth. The Curie temperature and cutoff wavelength were measured.

Longitudinal and Transverse Electrocaloric Effects in Glycinium Phosphite Ferroelectric

A modified proton ordering model of glycinium phosphite ferroelectric, which involves the piezoelectric coupling of the proton and lattice subsystems, is used for the investigation of the electrocaloric effect. The model also accounts for the dependence of the effective dipole moment on a hydrogen bond on an order parameter, as well as a splitting of parameters of the interaction between pseudospins in the presence of shear stresses. In the two-particle cluster approximation, the influence of longitudinal and transverse electric fields on components of the polarization vector and the dielectric permittivity tensor, as well as on thermal characteristics of the crystal, is calculated. Longitudinal and transverse electrocaloric effects are studied. The calculated electrocaloric temperature change is quite small, about 1K; however, it can change its sign under the influence of a transverse field.

Impact of synchrotron X-ray radiation damage on a molecular ferroelectric crystal.

The small-molecule crystallographic community has recently begun to assess the radiation damage impact of high intensity beams on samples. Bogdanov et al. [Acta Cryst. (2021), B77, 365–370] investigate the radiation damage impact on molecular ferroelectric crystal glycinium phosphite.

Phase transition in an organic ferroelectric: glycinium phosphite, with and without X-ray radiation damage.

Thermal evolution of an organic ferroelectric, namely, glycinium phosphite, was probed by multi-temperature single-crystal diffraction using synchrotron radiation and also by a similar experiment with a laboratory X-ray diffractometer. Both series of measurements showed a transition from the paraelectric to the ferroelectric state at nearly the same temperature, Tc= 225 K. Temperature evolution of the unit-cell parameters and volume are drastically different for the synchrotron and laboratory data. The latter case corresponds to previous reports and shows an expected contraction of the cell on cooling. The data collected with the synchrotron beam show an abnormal nonlinear increase in volume on cooling. Structure analysis shows that this volume increase is accompanied by a suppression of scattering at high angles and an apparent increase of the anisotropic displacement parameters for all atoms; we therefore link these effects to radiation damage accumulated during consecutive data collections. The effects of radiation on the formation of the polar structure of ferroelectric glycinium phosphite is discussed together with the advantages and drawbacks of synchrotron experimentation with fine temperature sampling.

Structural, conductivity and DFT studies of L-Histidinium phosphite – Ferroelectric phosphite single crystal

L-Histidinium phosphite [C6N3O2H10]+. [HPO3H]- abbreviated as HPI, is a semi-organic nonlinear optical material. In the present work HPI crystals were grown from the aqueous solution of HPI by slow evaporation technique. Single crystal XRD (SXRD) reveals that the resulting crystals predominantly exhibit monoclinic structure with space group P21. Sharp and well-defined peaks of the powder XRD pattern attested the good crystallinity of HPI and the pattern is in agreement with SXRD results. The different modes of vibrations of molecular groups and functional groups present in the HPI crystal was investigated using IR spectra. It is evident from the UV–Vis spectrum that HPI is transparent in the examined frequency regime. The TG-DTA studies ascertain that the crystal is thermal stable till 230 ​°C. A.C. and D.C. conduction mechanism in the grown crystals were studied from 119 ​K to 380 ​K for 1 ​kHz to 1 ​MHz frequency range. The pattern suggests that there is ferroelectric to paraelectric transition at 270 ​K. This transition temperature is higher than the glycine phosphite crystals. Detailed insight about the conduction mechanism in HPI crystals was analyzed by complex impedance and modulus studies. Density functional theory was applied to know in detail about the structure and non-linear optical characteristics of the grown crystal and it attested that HPI is NLO active at room temperature.

IR and Raman spectra of strong OHO hydrogen bonds

The work outlines general ideas on how the frequency and the intensity of proton vibrations of O-H⋅⋅⋅O hydrogen bonding are formed as the bond evolves from weak to maximally strong bonding. The Raman spectra of glycinium phosphite and protonated di-methylformamid possessing strong and maximally strong hydrogen bonds were obtained in the temperature region of 5 K – 300 K. It is shown that strong bonding is formed only as a result of a particular chemical state of the donor and the acceptor and that the registration of proton vibrations requires low temperatures or high pressures. The dependence of the proton vibrational frequency is schematically presented as a function of the rigidity of O-H⋅⋅⋅O bonding.

Вплив напруг σ5, σ6 і електричного поля E1 на термодинамічні характеристики сегнетоактивних матеріалів GPI

Для дослiдження ефектiв, що виникають пiд дiєю зовнiшнiх зсувних напруг q5, q6 i електричного поля E1, використано модифiковану модель кристала GPI шляхом врахування п’єзоелектричного зв’язку структурних елементiв, якi впорядковуються, з деформацiями

Impact of shock waves on vibrational and structural properties of glycine phosphite

This article carries the findings of the effect of shock waves on glycine phosphite (GPI) powder samples which have been investigated under pre and post shock loaded conditions with the shock pulses of 50 and 100 at the Mach number of 2.2. Molecular structural stability and crystal structural stabilities have been established by Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffractometry (XRD). From XRD studies, it has been observed that there is change in crystalline peak intensity, peak distortion and formation of new peaks in shock wave loaded samples whereas no alteration in the original crystal system. There is no change observed in FTIR profiles at shock loaded conditions. The obtained crystallographic studies prove with substantial evidence that the crystal has molecular stability and stable crystallographic structure against the impact of applied shock waves. On the other hand, many of the crystalline planes have disappeared and re-appeared with respect to number of shock waves but maintaining the same crystallographic phase. From the shock wave impact study; the authors suggest that GPI crystal, particularly (21-1) orientation, is suitable for devices used in harsh environment and high power laser application due to the relative stability of the crystalline properties.

Growth, structural, dielectric and optical characteristics of glycine phosphite single crystals

Interesting compounds are formed when glycine reacts with inorganic materials. These compounds exhibit phase transitions with exciting dielectric and elastic properties. In this aspect, glycine with orthophosphorus acid forms glycine phosphite (GPI) single crystals. Good quality, optical transparent glycine phosphite (GPI) single crystals are grown from aqueous solution. GPI crystals have a wide range of nonlinear optical applications. The present work focuses on the growth of GPI from its aqueous solution by slow evaporation method. The PXRD (powder XRD) pattern recorded at ambient temperature shows the single phase nature of the grown GPI crystals and it exists in the monoclinic system with space group P21/a. Etching studies were carried out to know more about the growth morphology and FTIR spectra shows the presence of a variety of normal mode vibration of GPI crystals. Dielectric studies were carried out from 100 K to 383 K. the ferroelectric to para electric transition was observed at 201 K. The dielectric relaxation of the grown crystals was studied using Debye fitting. The activation energy associated with the transition was also calculated. As the GPI crystals are paraelectric at room temperature, no second order non linearity was observed.

Field-deformational effects in GPI ferroelectric materials

ABSTRACTThe effects appearing under the simultaneously applied mechanical stress and electric field are studied. We use a model of glycinium phosphite ferroelectric, modified by taking into account of piezoelectric coupling of the ordering structure elements with the lattice strains . Within the framework of two-particle cluster approximation, the components of polarization vector and the static dielectric permittivity tensor as well as piezoelectric and thermal characteristics are calculated. The separate and simultaneous effects of shear stress and electric field on the ferroelectric phase transition in the crystal are studied and mutually compared.

Calculation of transverse piezoelectric characteristics of quasi-one-dimensional glycine phosphite ferroelectric

Calculation of transverse piezoelectric characteristics of quasi-one-dimensional glycine phosphite ferroelectric

Anisotropy of the electron spin–lattice relaxation. PO32− radical in glycinium phosphite gly·H3PO3 crystal

Electron spin–lattice relaxation has been measured for PO32− radical in glycinium phosphite gly·H3PO3 crystal and its deuterated analogue in temperature range 40–300 K. Angular dependence of the relaxation rate was measured in three crystal planes at room temperature. The Debye cut-off temperature has been calculated as ΘD = 97 K, which indicates that the temperature dependence of 1/T1 is governed by radical local vibrations localized in optical phonon modes range. Theories of possible 1/T1 angular dependence are reviewed. The anisotropy of spin–lattice relaxation rate in our crystal is assumed to be a result of local magnetic field fluctuations due to electron–proton dipolar coupling. Theoretical evaluation of 1/T1 were performed for coupling with protons at distances up to 0.46 nm. Not perfect agreement was found with motion correlation time τc = 2·10−9 s.

Influence of Longitudinal Electric Field on Thermodynamic Properties of NH3CH2COOH·H2PO3 Ferroelectric

Using a modified model of ferroelectric glycine phosphite by considering the piezoelectric coupling with strains e1 within the two-particle cluster approximation, the expressions for the polarization vector, static dielectric permittivity tensor, piezoelectric coefficients, and elastic constants of the crystal in the presence of a longitudinal electric field E2 are calculated. An analysis of the influence of this field on thermodynamic characteristics of the crystal is carried out. The dependence of effective dipole moments on order parameters is taken into account. This allowed us to agree the effective dipole moments in the ferro- and paraelectricphases and to describe the smearing of phase transition under the influence of an electric field. The satisfactory quantitative description of the available experimental data for these characteristics has been obtained at the proper choice of the model parameters.

Birefringence, Photo luminous, Optical Limiting and Third Order Nonlinear Optical Properties of Glycinium Phosphite (GlP) Single Crystal: A potential Semi Organic Crystal for Laser and Photonics Applications

Birefringence, Photo luminous, Optical Limiting and Third Order Nonlinear Optical Properties of Glycinium Phosphite (GlP) Single Crystal: A potential Semi Organic Crystal for Laser and Photonics Applications

Thermal, dielectric, and surface analysis of NaDP doped glycine phosphite single crystals

Transparent, unidirectional single crystals of sodium dihydrogen phosphate-doped glycine phosphite (NaDP–GPI) are grown by the Sankaranarayanan-Ramasamy method. The good quality crystal is obtained under controlled thermal conditions. The functional groups and melting temperature of NaDP–GPI single crystals are analysed. The phase transition temperature of NaDP–GPI is calculated from the dielectric studies. The mound-like patterns are observed on the surface of the crystal. The growth process under the controlled thermal condition was observed by optical studies. The obtained results are discussed in detail.

Thermal, dielectric, and surface analysis of NaDP doped glycine phosphite single crystals

Thermal, dielectric, and surface analysis of NaDP doped glycine phosphite single crystals