NMR study of the order–disorder phase transitions of KHCO3 and KDCO3 single crystals

Lim, Ae Ran; Jeong, Se–Young

doi:10.1016/j.jssc.2005.12.029

Cited by 5 publications

(8 citation statements)

References 30 publications

(45 reference statements)

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“…This increase of the 2 H spin-lattice relaxation rate corresponds to a dip in the behavior of the relaxation time as a function of temperature, as reported in Ref. [17].…”

Section: Critical Behavior Of the 2 H Zeeman Relaxation Timesupporting

confidence: 80%

“…Whether the phase transition of KDCO 3 is continuous ('second order') [24] or discontinuous ('first order') [17] is still a controversial point. In fact, the small step in the order parameter ρ near T c (Fig.…”

Section: Discussionmentioning

confidence: 99%

“…Nuclear magnetic resonance methods have been successful in studying XHCO 3 compounds since all nuclei (except oxygen when not enriched in 17 O) have a spin. The different nuclei give complementary information at different spatial and time scales depending on the type of interaction.…”

Section: Introductionmentioning

confidence: 99%

“…Dips in the spin-lattice and spin-spin relaxation times of 1 H, 39 K, 2 H NMR were evidenced near the transition temperature of KHCO 3 or KDCO 3 from single crystal NMR. [16,17] The position and changes of the number of lines were also recorded as a function of temperature. Far from the transition, the temperature dependence of the 39 K relaxation rate was interpreted as high-order Raman processes, and activation energies were evaluated from 1 H, 39 K and 2 H spinlattice relaxation curves as a function of temperature.…”

Section: Introductionmentioning

confidence: 99%

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Critical behavior of KDCO₃ from ²H and ³⁹K single crystal NMR

Odin¹

2007

Magnetic Reson in Chemistry

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Potassium hydrogenocarbonate KDCO3 presents an order/disorder phase transition at Tc approximately 353 K. The critical behavior of this phase transition was studied by single crystal 2H and 39K NMR. The evolution of the order parameter as a function of temperature is quantified, and the critical exponent was determined, indicating a transition close to a tricritical point. The 2H Zeeman relaxation rate is strongly increased near the transition temperature. By calculating the noncritical contribution to the Zeeman relaxation rate, we show that the observed relaxation rate clearly presents a pseudo-divergent behavior near Tc, with a logarithmic singularity. The nature of the phase transition is discussed in the light of these results.

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“…This increase of the 2 H spin-lattice relaxation rate corresponds to a dip in the behavior of the relaxation time as a function of temperature, as reported in Ref. [17].…”

Section: Critical Behavior Of the 2 H Zeeman Relaxation Timesupporting

confidence: 80%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Critical behavior of KDCO₃ from ²H and ³⁹K single crystal NMR

Odin¹

2007

Magnetic Reson in Chemistry

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“…Until very recently, 39 K NMR has seen very few applications in the solid state because of difficulties in obtaining spectra, as both isotopes, 39 K and 41 K (natural abundance of 93.7 and 6.3%, respectively), are spin- 3 / 2 quadrupolar nuclei with low magnetogyric ratios (absolute resonance frequencies of Ξ = 4.6664 MHz for 39 K and Ξ = 2.5613 MHz for 41 K). The total number of publications involving the more easily observed 39 K nucleus is relatively small and involves results on potassium halides (cubic lattice = zero quadrupole interactions), several studies of single crystals, − and powders. − Most of the studies were performed in magnetic fields of intermediate strengths of 7−11 T, with a single study reporting 39 K NMR in some minerals at 21 T . Two recent high-field studies (19.6 T) were devoted to examination of potassium tetraphenylborates and the detection of potassium cations bound to G-quadruplex structures found in telomeric DNA…”

Section: Introductionmentioning

confidence: 99%

³⁹K NMR of Solid Potassium Salts at 21 T: Effect of Quadrupolar and Chemical Shift Tensors

Moudrakovski

Ripmeester

2007

J. Phys. Chem. B

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39K Solid State NMR spectra (static and magic angle spinning (MAS)) on a set of potassium salts measured at 21.14 T show that the chemical shift range for K(+) ions in diamagnetic salts is well in excess of 100 ppm contrary to previous assumptions that it was quite small. Inequivalent potassium sites in crystals can be resolved through differences in chemical shifts, with chemically similar sites showing differences of over 10 ppm. The quadrupolar coupling constants obtained from MAS and solid echo experiments on powders cover the range from zero for potassium in cubic environments in halides to over 3 MHz for the highly asymmetric sites in K2CO3. Although the quadrupolar effects generally dominate the 39K spectra, in several instances, we have observed subtle but significant contributions of chemical shift anisotropy with values up to 45 ppm, a first such observation. Careful analysis of static and MAS spectra allows the observation of the various chemical shift and quadrupole coupling tensor components as well as their relative orientations, thereby demonstrating that high-field 39K NMR spectroscopy in the solid state has a substantial sensitivity to the local environment with parameters that will be of considerable value in materials characterization and electronic structure studies.

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Thermal and ac electrical properties of N -methylanthranilic acid below room temperature

Abdel‐Kader

Basha

Ramzy

et al. 2018

Journal of Physics and Chemistry of Solids

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NMR study of the order–disorder phase transitions of KHCO3 and KDCO3 single crystals

Cited by 5 publications

References 30 publications

Critical behavior of KDCO₃ from ²H and ³⁹K single crystal NMR

Critical behavior of KDCO₃ from ²H and ³⁹K single crystal NMR

³⁹K NMR of Solid Potassium Salts at 21 T: Effect of Quadrupolar and Chemical Shift Tensors

Thermal and ac electrical properties of N -methylanthranilic acid below room temperature

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NMR study of the order–disorder phase transitions of KHCO3 and KDCO3 single crystals

Cited by 5 publications

References 30 publications

Critical behavior of KDCO3 from 2H and 39K single crystal NMR

Critical behavior of KDCO3 from 2H and 39K single crystal NMR

39K NMR of Solid Potassium Salts at 21 T: Effect of Quadrupolar and Chemical Shift Tensors

Thermal and ac electrical properties of N -methylanthranilic acid below room temperature

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Product

Resources

About

Critical behavior of KDCO₃ from ²H and ³⁹K single crystal NMR

Critical behavior of KDCO₃ from ²H and ³⁹K single crystal NMR

³⁹K NMR of Solid Potassium Salts at 21 T: Effect of Quadrupolar and Chemical Shift Tensors