0000000000061696
AUTHOR
Georg Levchenko
showing 4 related works from this author
Pressure effect on temperature induced high-spin–low-spin phase transitions
2002
The effect of hydrostatic pressure on the transition temperature and the hysteresis widths of first-order spin crossover phase transitions is considered in the frame of the mean field theory and on the basis of the scope of recent pressure experiments. Relevant parameters for a qualitative description of the behaviour of spin transition compounds under pressure are derived and analysed.
Spin crossover behavior under pressure of Fe(PM-L)2(NCS)2 compounds with substituted 2′-pyridylmethylene 4-anilino ligands
1998
Abstract New iron(II) spin crossover systems with large aromatic ligands, based on 2′-pyridylmethylene 4-anilino units, have been synthesized and studied. The whole range of spin crossover behavior has been observed, starting from pure high-spin to more or less complete gradual transitions and finally to discontinuous type transitions with both small and large hysteresis. Magnetic measurements under pressure have revealed that two of the compounds exhibit pressure-induced new phases with larger hysteresis than at atmospheric pressure. For one of the compounds the formation of this new phase is irreversible and the hysteresis width is ∼100 K, as compared to 37 K before applying pressure.
Pressure Effect on Spin Crossover in [Fe(phen)2(NCS)2] and [CrI2(depe)2]
2004
In the present article, we discuss the results of investigations of the influence of hydrostatic pressure (up to 1.2 GPa) on the spin transition behavior in [Fe(phen)2(NCS)2] polymorph II and [CrI2(depe)2]. It is demonstrated that pressure effect studies are very helpful in elucidating the mechanism of cooperative dynamic electronic structure phenomena accompanied by significant volume changes. Application of hydrostatic pressure serves as a tool for modifying the ligand field strength in a controlled manner.
The influence of hydrostatic pressure on hysteresis phase transition in spin crossover compounds
1999
Abstract The effect of hydrostatic pressure on the transition temperature and the hysteresis widths of first order spin crossover phase transitions has been studied. A decrease as well as an increase of the hysteresis width with increasing pressure was reported in the literature. The increase of width with increasing pressure contradicts the expectation derived from mean field theory. We remeasured the pressure dependence of the temperature hysteresis of the compound [Fe(phy)2](BF4)2 (phy=1, 10-phenanthroline-2-carbaldehydephenylhydrazone). The spin transition temperatures at ambient temperature are T ↑ 1/2 =289±1 K, T ↓ 1/2 =283±1 K . An increase of the hysteresis width of d Δ T 1/2 / d p=…