Static magnetic susceptibility in finite-density $$SU\left( 2\right) $$ lattice gauge theory

We study static magnetic susceptibility $$\chi (T, \mu )$$ χ ( T , μ ) in SU(2) lattice gauge theory with $$N_f = 2$$ N f = 2 light flavours of dynamical fermions at finite chemical potential $$\mu $$ μ . Using linear response theory we find that SU(2) gauge theory exhibits paramagnetic behavior in both the high-temperature deconfined regime and the low-temperature confining regime. Paramagnetic response becomes stronger at higher temperatures and larger values of the chemical potential. For our range of temperatures $$0.727 \le T/T_c \le 2.67$$ 0.727 ≤ T / T c ≤ 2.67 , the first coefficient of the expansion of $$\chi \left( T, \mu \right) $$ χ T , μ in even powers of $$\mu /T$$ μ / T around $$\mu =0$$ μ = 0 is close to that of free quarks and lies in the range $$(2, \ldots , 5) \cdot 10^{-3}$$ ( 2 , … , 5 ) · 10 - 3 . The strongest paramagnetic response is found in the diquark condensation phase at $$\mu >m\pi /2$$ μ > m π / 2 .

Соединение HoFeTi-=SUB=-2-=/SUB=-O-=SUB=-7-=/SUB=-: cинтез, особенности кристаллической структуры и магнитные свойства

Polycrystalline HoFeTi2O7 samples were obtained by solid-phase synthesis and studied by X-ray diffraction, gamma resonance, and SQUID methods. The characteristics of structural properties are presented, indicating the distribution of iron atoms over nonequivalent crystallographic positions and their uneven filling in the positions mixed with titanium. Spin disorder formed by mixing magnetic and nonmagnetic ions, spatial inhomogeneity of interactions that determine the magnetic structure in the crystal leads to the formation of competing exchange magnetic interactions between the nearest neighbors, frustration of magnetic bonds and the absence of long-range magnetic order. It has been shown that the temperature dependence of the static magnetic susceptibility at low temperatures has features characteristic of the spin glass magnetic state.

New Iron(II) Complexes [Fe(HC(Pz)3)2]A2 with Spin-Crossover

Three new coordination compounds of iron (II), [Fe (HC(Pz)3)2](C8H5O4)2.C8H6O4(I), [Fe (HC(Pz)3)2](C10H7SO3)2.2H2O (II) and Fe (HC(Pz)3)2](C12H25SO4)2(III), where HC(Pz)3is the tridentate chelatortris(pyrazol-1-yl) methane, have been synthesized and investigated by X-ray structure analysis, electronic and IR spectroscopy, static magnetic susceptibility method. The magnetochemical study of complexes I–III in the interval from 300 to 500 K showed that they possessed the high-temperature spin crossover1A1↔5T2accompanied by thermochromism (the pink ↔ white color change).