Magnetic systems at criticality: different signatures of scaling

Different aspects of critical behaviour of magnetic materials are presented and discussed. The scaling ideas are shown to arise in the context of purely magnetic properties as well as in that of thermal properties as demonstrated by magnetocaloric effect or combined scaling of excess entropy and order parameter. Two non-standard approaches to scaling phenomena are described. The presented concepts are exemplified by experimental data gathered on four representatives of molecular magnets.Comment: 33 pages, 16 figure

Studies on magnetic properties of unique molecular magnet {[FeII(pyrazole)4]2[NbIV(CN)8]⋅4H2O}n\{[Fe^{II}(pyrazole)_4]_2[Nb^{IV}(CN)_8]\cdot4H_2O\}_n

In this paper magnetic properties of hybrid inorganic-organic compound {[FeII(pyrazole)4]2[NbIV(CN)8]∙4H2O}n are presented. This is a three dimensional molecular magnet with well localized magnetic moments, which make it a suitable candidate for testing magnetic models. In order to characterize the magnetic properties of the above compound we performed the AC/DC magnetometry in the range 0-5 T. The special attention was paid to the phase transition at 7.9 K. The study in magnetic field supports magnetic ordering below 7.9 K

Photo-induced relaxation of magnetization in molecular magnet

The experimental study of photo-induced magnetization of hybrid molecular magnet containing cobalt(II) and tungsten(V) magnetic centers bridged by 4,40 -bpy and CN− is presented. The observed increase in magnetization rate is attributed to the defects due to inter-valence transfer between CoIIWV *) CoIIIWIV. The time evolution of magnetization is parameterized by the power law rather than exponential function

Enforcing Multifunctionality: A Pressure-Induced Spin-Crossover Photomagnet

Photomagnetic compounds are usually achieved by assembling preorganized individual molecules into rationally designed molecular architectures via the bottom-up approach. Here we show that a magnetic response to light can also be enforced in a nonphotomagnetic compound by applying mechanical stress. The nonphotomagnetic cyano-bridged Fe^II–Nb^IV coordination polymer {[Fe^II(pyrazole)₄]₂[Nb^IV(CN)₈]·4H₂O}_<i>n</i> (<b>FeNb</b>) has been subjected to high-pressure structural, magnetic and photomagnetic studies at low temperature, which revealed a wide spectrum of pressure-related functionalities including the light-induced magnetization. The multifunctionality of <b>FeNb</b> is compared with a simple structural and magnetic pressure response of its analog {[Mn^II(pyrazole)₄]₂[Nb^IV(CN)₈]·4H₂O}_<i>n</i> (<b>MnNb</b>). The <b>FeNb</b> coordination polymer is the first pressure-induced spin-crossover photomagnet

Photomagnetism in cyano-bridged hexanuclear clusters [MnII(bpy)2]4[MIV(CN)8]2.xH2O (M = Mo, x = 14, and M = W, x = 9)

The magnetic and photomagnetic properties of two cyano-bridged, [Mn(bpy)2]4[Mo(CN)8]2·14H2O (1) and [Mn(bpy)2]4[W(CN)8]2·9H2O (2) (bpy = 2,2'-bipyridyl), hexanuclear clusters (hereafter named MnII4MIV2) have been investigated..