Metal-Formate Framework Stiffening and Its Relevance to Phase Transition Mechanism.

In the last decade, one of the most widely examined compounds of motal-organic frameworks was undoubtedly ((CH)NH)(Zn(HCOO)), but the problem of the importance of framework dynamics in the order-disorder phase change of the mechanism has not been fully clarified. In this study, a combination of temperature-dependent dielectric, calorimetric, IR, and Raman measurements was used to study the impact of ((CH)NH)(Zn(DCOO)) formate deuteration on the phase transition mechanism in this compound. This deuteration led to the stiffening of the metal-formate framework, which in turn caused an increase in the phase transition temperature by about 5 K.

Temperature-dependent studies of [(CH3)2NH2][Fe(III)M(II)(HCOO)6] frameworks (M(II) = Fe and Mg): structural, magnetic, dielectric and phonon properties.

Novel heterometallic formate [(CH3)2NH2][Fe(III)Mg(II)(HCOO)6] (DMFeMg) was prepared and characterized by single crystal X-ray diffraction, DSC, dielectric, magnetic susceptibility, Raman and IR methods. We also report thermal, Raman and IR studies of the known compound [(CH3)2NH2][Fe(III)Fe(II)(HCOO)6] (DMFeFe). DMFeMg crystallizes in the niccolite structure (P3[combining macron]1c space group).

Synthesis and characterization of [(CH3)2NH2][Na0.5Cr0.5(HCOO)3]: a rare example of luminescent metal-organic frameworks based on Cr(III) ions.

A novel formate [(CH3)2NH2][Na0.5Cr0.5(HCOO)3] (DMNaCr) was prepared by a solvothermal method.

Synthesis and order-disorder transition in a novel metal formate framework of [(CH₃)₂NH₂]Na(0.5)Fe(0.5)(HCOO)₃].

We report the synthesis, crystal structure, thermal, dielectric, Raman, infrared, and magnetic properties of [(CH3)2NH2][Na(0.5)Fe(0.5)(HCOO)3] (DMNaFe), the first metal formate framework templated by organic cations, presenting an ABO3 perovskite architecture with NaO6 octahedra as building blocks of the framework.

Experimental evidence of the role of compound counting processes in random walk approaches to fractional dynamics.

We present dielectric spectroscopy data obtained for gallium-doped Cd(0.99)Mn(0.01)Te:Ga mixed crystals, which exhibit a very special case of the two-power-law relaxation pattern with the high-frequency power-law exponent equal to 1.

The frequency-domain relaxation response of gallium doped Cd(1-x)Mn(x)Te.

In this paper the complex dielectric permittivity of gallium doped Cd(0.99)Mn(0.01)Te mixed crystals is studied at different temperatures.

Overshooting and undershooting subordination scenario for fractional two-power-law relaxation responses.

In this paper, we propose a transparent subordination approach to anomalous diffusion processes underlying the nonexponential relaxation. We investigate properties of a coupled continuous-time random walk that follows from modeling the occurrence of jumps with compound counting processes. As a result, two different diffusion processes corresponding to over- and undershooting operational times, respectively, have been found.

Properties of the relaxation time distribution underlying the Kohlrausch-Williams-Watts photoionization of the DX centers in Cd(1-x)Mn(x)Te mixed crystals.

In this paper we clarify the relationship between the relaxation rate and relaxation time distributions underlying the Kohlrausch-Williams-Watts (KWW) photoconductivity build-ups in indium- and gallium-doped Cd(1-x)Mn(x)Te mixed crystals. We discuss the role of asymptotic properties of the corresponding probability density functions. We show that the relaxation rate distribution, as a completely asymmetric α-stable distribution, leads to an infinite mean value of the effective relaxation rate.

On the relaxation rate distribution of the photoionized DX centers in indium doped Cd(1-x)Mn(x)Te.

It was recently shown that the kinetics of persistent photoconductivity (PPC) build-up in indium doped Cd(1-x)Mn(x)Te are non-exponential and can be described solely by the stretched-exponential function. The non-exponentiality is attributed to the indium related DX centers present in the materials. In order to explain this observation, low temperature photoconductivity build-up was studied for Cd(1-x)Mn(x)Te:In of two different manganese contents.