Effect of Structural Changes on DC Ionic Conductivity of Rubidium Nitrate Single Crystals

Chary, A. Sadananda; Reddy, S. Narender

doi:10.1002/(sici)1521-3951(199808)208:2<349::aid-pssb349>3.0.co;2-5

Cited by 12 publications

(2 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A plot of conductance σ(T) of RbNO crystal versus 10 3 /T on a semi-log scale is presented in figure 6 in a large temper ature scale, from room temperature to RbNO 3 -crystal melting temperature. The similar measurements have been done also in literature [23,24]. The dependence of σ on T is in strict agreement with our IS measurements, described above, and displays anomalies at temperatures corresponding to SPT.…”

Section: Ionic Conductivity In Wide Band-gap Semiconductorssupporting

confidence: 91%

Reversible amorphization under ac electric field and character of conductivity of TlInTe₂ crystal at ionic conductivity temperature

Alekperov

Nakhmedov

Najafov

et al. 2019

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

Temperature dependence of x-ray diffraction (XRD) investigation of crystal over a wide temperature interval (300–570 K) reveals a sequence of phase transitions, including ferroelectric (300–370 K) and ionic conductivity (485–500 K) phase transitions (FPT and ICPT), which are caused by shifting and thermal activation of ions inside of Thomson cube cages of unit cells. The results of XRD versus temperature studies confirm our previous investigations of this crystal (Alekperov O Z et al 2018 J. Appl. Phys. 123 135701) by means of the impedance spectroscopy (IS) method. Temperature dependence of almost all the reflexes’ intensity in XRD data was investigated up to a few tens of Kelvin higher than the so called ionic conductivity (IC) temperature. Intensities of almost all reflexes decrease with increasing the temperature up to K, and reach a minimum at K, corresponding to the maximum of at FPT. The same strong decrease of intensity takes place for reflex 110 at K, which corresponds to Tl+ -ion activation along the chain direction of crystal. A small decrease of the 221 reflex intensity at IC temperature is also observed. The reflexes, intensities of which were almost not changed, are 220 and 440. Room temperature XRD measurements, which were performed in wide temperature interval under alternate electric field with amplitude and frequency 0.5 MHz applied along c-direction of the crystal . Our measurements show a partial amorphization of structure which relaxes back during a few days gradually to more perfect tetragonal structure with XRD reflex intensities higher than the initial reflexes. By analyzing the results of IS and conductivity measurements in wide- and narrow-gap semiconductors on the example of rubidium nitrate () and thallium indium telluride () crystals correspondingly, it was shown that the definition of super ionic conductivity is completely inapplicable, since a high conductivity in these semiconductors originates from increase of free electrons concentration.

show abstract

Section: Ionic Conductivity In Wide Band-gap Semiconductorssupporting

confidence: 91%

Reversible amorphization under ac electric field and character of conductivity of TlInTe₂ crystal at ionic conductivity temperature

Alekperov

Nakhmedov

Najafov

et al. 2019

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

show abstract

“…However, Yamamoto et al [142] proposed that the coupling between the orientation of anions and shear strain played an important role in this phase transition, both structures having an eight-fold orientational disorder. Additionally, Chary and Reddy [149] and references therein studied the ionic conductivity versus the temperature. They noticed an increase in conductivity in IV-RbNO3…”

Section: Crystal Structure Polymorphism and Phase Transitionmentioning

confidence: 99%

Polymorphism, crystal growth, crystal morphology and solid-state miscibility of alkali nitrates

Benages‐Vilau

Calvet

Cuevas‐Diarte

2013

Crystallography Reviews

View full text Add to dashboard Cite

In this review, we recollect and discuss the most relevant advancement in crystallographic aspects of alkali nitrates compounds published since 1975, the year of publication of the last review by Rao et al. about some topics discussed here. This review is focused in five nitrate compounds of the first periodic table column: LiNO3, NaNO3, KNO3, RbNO3 and CsNO3. For each one, we have compiled the information about crystal structure, polymorphism and phase transition, crystal growth and crystal morphology, and the phase diagram and solid-state miscibility results. Considerable numbers of papers have been published in the last 40 years, in particular in relation to binary phase diagrams and solidstate miscibility of alkali nitrates. A variety of phase diagram descriptions appears in the 10 possible binary combinations for the five compounds. To finish, we discuss and propose a geometric model in order to explain the different binary phase diagrams observed between these compounds. 4 2. Lithium nitrate 2.1. Crystal structure, polymorphism and phase transitions As Rao et al. [6] have shown, lithium nitrate crystallizes in rhombohedral (calcite type), R3 � c group with Z = 6, a = 4.692Å and c = 15.22Å at 298 K. There is no evidence for a phase transition in the thermodynamic properties from 298K to the melting point.[10] However, discontinuities in the absorption coefficient [11] and changes in electric properties [12] may indicate an orientational disorder transition on nitrate groups just like NaNO3 or NH4NO3.After Rao et al., onlyWu et al. [13] determined the LiNO3 crystal structure. The authors give a significant variation in the c-parameter as can be seen in Table 1. The unit cell determined by Wu et al. [13] is presented in Figure 1, where blue spheres are lithium ions and red spheres are oxygen atoms. These authors grew the crystal from the melt and despite not having a good single crystal they were able to determine its structure. According to them, LiNO3 is isostructural to both calcite (CaCO3) and nitratine (NaNO3). No evidence has been found for a high-temperature phase. Moreover, Stromme [33] modelled a positional ordered equilibrium structure of LiNO3 at all temperatures.Accordingly, LiNO3 has only one structure as a function of temperature, as is recollected in Table 1. Crystal growthWe have not found any paper related to anhydrous lithium nitrate growth because it is deliquescent. Nonetheless, Chernov and Sipyagin [7] gave some kinetic data for LiNO3 • 3H2O compound, which is not of interest for this review. MorphologyAs far as we know, neither theoretical nor experimental morphology is reported for lithium nitrate crystals. However, we expect that the theoretical growth morphology determined by the Bravais-Friedel-Donnay-Harker (BFDH) method will be equal to that of calcite [34] and nitratine [35] because they are isostructural crystals. Therefore, {012}, {012 � } and {001} forms appear in the theoretical growth morphology (Figure 2).

show abstract

The phase diagram of CsNO3–RbNO3

Wacharine

Hellali

Zamali

et al. 2011

J Therm Anal Calorim

View full text Add to dashboard Cite

Effect of Structural Changes on DC Ionic Conductivity of Rubidium Nitrate Single Crystals

Cited by 12 publications

References 7 publications

Reversible amorphization under ac electric field and character of conductivity of TlInTe₂ crystal at ionic conductivity temperature

Reversible amorphization under ac electric field and character of conductivity of TlInTe₂ crystal at ionic conductivity temperature

Polymorphism, crystal growth, crystal morphology and solid-state miscibility of alkali nitrates

The phase diagram of CsNO3–RbNO3

Contact Info

Product

Resources

About

Effect of Structural Changes on DC Ionic Conductivity of Rubidium Nitrate Single Crystals

Cited by 12 publications

References 7 publications

Reversible amorphization under ac electric field and character of conductivity of TlInTe2 crystal at ionic conductivity temperature

Reversible amorphization under ac electric field and character of conductivity of TlInTe2 crystal at ionic conductivity temperature

Polymorphism, crystal growth, crystal morphology and solid-state miscibility of alkali nitrates

The phase diagram of CsNO3–RbNO3

Contact Info

Product

Resources

About

Reversible amorphization under ac electric field and character of conductivity of TlInTe₂ crystal at ionic conductivity temperature

Reversible amorphization under ac electric field and character of conductivity of TlInTe₂ crystal at ionic conductivity temperature