LaM 1.5 II MnFeO 6 manganitoferrites (M II = Mg, Ca, Sr, Ba) have been synthesized by ceramic technology from lanthanum oxide, manganese(III) oxide, iron(III) oxide, and alkali-earth carbonates. X-ray powder diffraction shows that these compounds crystallize in cubic crystal system with the following unit cell parameters: for LaMg 1.5 MnFeO 6 : a = 20.232 ± 0.032 Å, V 0 = 8281.642 ± 0.096 Å 3 , Z = 10, ρ X = 7.38 g/cm 3 , ρ pycn = 7.29 ± 0.06 g/cm 3 ; for LaCa 1.5 MnFeO 6 : a = 20.056 ± 0.017 Å, V 0 = 8067.388 ± 0.051 Å 3 , Z = 8, ρ X = 5.89 g/cm 3 , ρ pycn = 5.78 ± 0.06 g/cm 3 ; for LaSr 1.5 MnFeO 6 : a = 20.117 ± 0.021 Å, V 0 = 8141.223 ± 0.063 Å 3 , Z = 8, V u.c. 0 = 1017.653 ± 0.008 Å 3 , ρ X = 6.64 g/cm 3 , ρ pycn = 6.56 Å 0.08 g/cm 3 ; for LaBa 1.5 MnFeO 6 : a = 20.361 ± 0.025 Å, V 0 = 8441.066 ± 0.075 Å 3 , Z = 8, ρ X = 7.31 g/cm 3 , ρ pycn = 7.25 ± 0.07 g/cm 3 .

LaM 3 I CrMnO6 (MI = Li, Na) and LaM 3 II CrMnO7.5 (MII = Mg, Ca) chromitomanganites were synthesized by ceramic technology from lanthanum oxide, chromium(III) oxide, manganese(III) oxide, lithium carbonate, sodium carbonate, magnesium carbonate, and calcium carbonate. X-ray powder diffraction shows that these compounds crystallize in cubic or tetragonal systems with the following unit cell parameters: for LaLi3CrMnO6 (cubic): a = 10.98 Å, V ○ = 1323.75 Å3, Z = 8, V u.c ○ = 165.47Å3, ρX = 3.64, ρpycn= 3.60 ± 0.04 g/cm3; for LaNa3CrMnO6 (tetragonal): a = 10.96 Å, c = 15.73 Å, V ○ = 1889.51 Å3, Z = 16, V u.c ○ = 118.09 Å3, ρX = 5.77 g/cm3, ρpycn = 5.70 ± 0.07 g/cm3; LaMg3CrMnO7.5 (cubic), a = 10.98 Å, V ○ = 1322.31 Å3, Z = 8, V u.c ○ = 165.29 Å3, ρX = 4.41 g/cm3, ρpycn = 4.35 ± 0.07 g/cm3; and for LaCa3CrMnO7.5 (cubic): a = 10.97 Å, V ○ = 1319.78 Å3, Z = 8, V u.c pO = 164.97 Å3, ρX = 4.89 g/cm3, ρpycn = 4.85 ± 0.05 g/cm3.

По разработанному методу расчета вычислены стандартные энтальпии образования манганито-ферритов состава LnMIIMnFeO5.5 (Ln – редкоземельный элемент, MII – щелочно-земельный металл). Методом ионных инкрементов рассчитаны их стандартные энтропии и по уравнению Гиббса–Гельмгольца – их стандартные энергии Гиббса образования.

Manganite ferrites NdM 1.5 II MnFeO 6 (M II = Mg, Ca, Sr, Ba) were synthesized from neodymium(III), manganese(III), and iron(III) oxides and alkaline-earth metal carbonates by a ceramic technology. By grinding the obtained compounds in a ball mill, their nanostructured particles were produced, the sizes of which were determined with an electron microscope. X-ray diffraction study established that the nanostructured compounds crystallize in the cubic and tetragonal systems with the following lattice parameters: NdMg 1.5 MnFeO 6 (tetragonal): a = 10.955 Å, c = 17.848 Å, V 0 = 2141.975 Å 3 , Z = 16, V e1.cel1 0 = 133.873 Å 3 , ρ X-ray = 4.80 g/cm 3 , and ρ pycn = 4.76 ± 0.05 g/cm 3 ; NdCa 1.5 MnFeO 6 (cubic): a = 10.809 Å, V 0 = 1262.864 Å 3 , Z = 8, V e1.cel1 0 = 157.858 Å 3 , ρ X-ray = 4.32 g/cm 3 , and ρ pycn = 4.27 ± 0.03 g/cm 3 ; NdSr 1.5 MnFeO 6 (cubic): a = 10.911 Å, V 0 = 1298.953 Å 3 , Z = 8, V e1.cel1 0 = 162.369 Å 3 , ρ X-ray = 4.93 g/cm 3 , and ρ pycn = 4.88 ± 0.05 g/cm 3 ; and NdBa 1.5 MnFeO 6 (tetragonal): a = 11.011 Å, c = 18.001 Å, V 0 = 2182.479 Å 3 , Z = 16, V e1.cel1 0 = 136.405 Å 3 , ρ X-ray = 6.78 g/cm 3 , and ρ pycn = 6.75 ± 0.07 g/cm 3 .

Manganite ferrites NdM I MnFeO 5 (M I = Li, Na, K) were synthesized from neodymium(III), manganese(III), and iron(III) oxides and lithium, sodium, and potassium carbonates by a ceramic technology. By grinding the obtained compounds in a ball mill, their nanostructured particles were produced, the sizes of which were determined with an electron microscope. X-ray powder diffraction study and indexing established that the nanostructured compounds NdM I MnFeO 5 (M I = Li, Na, K) crystallize in the cubic system with the following lattice parameters: NdLiMnFeO 5 : a = 20.100 ± 0.034 Å, V 0 = 8120.60 Å 3 , Z = 10, V un.cell 0 = 812.06 Å 3 , ρ X-ray = 7.14 g/cm 3 , and ρ pycn = 7.09 ± 0.06 g/cm 3 ; NdNaMnFeO 5 : a = 20.102 ± 0.032 Å, V 0 = 8123.03 Å 3 , Z = 10, V un.cell 0 = 812.30 Å 3 , ρ X-ray = 7.11 g/cm 3 , and ρ pycn = 7.04 ± 0.06 g/cm 3 ; and NdKMnFeO 5 : a = 20.107 ± 0.011 Å, V 0 = 8129.09 Å 3 , Z = 10, V un.cell 0 = 812.91 Å 3 , ρ X-ray = 7.03 g/cm 3 , and ρ pycn = 6.95 ± 0.07 g/cm 3 .

The heat capacities of the new manganite ferrites NdMIMnFeO5 (MI = Li, Na) are investigated in the range of 298.15–673 K by dynamic calorimetry. It is found that in the investigated temperature range, C p ○ ∼ f(T) curves exhibit λ-shaped effects at 348 and 473 K for NdLiMnFeO5, and at 423 K for NdNaMnFeO5, corresponding probably to phase transitions of the second kind. Equations describing the experimentally obtained C p ○ ∼ f(T) curves are derived, and the temperature dependences of the investigated compounds’ thermodynamic functions, S○(T), H○(T) − H○(298.15), and Φ xx (T), are calculated.

The standard enthalpies of formation of LnM II MnFeO 5.5 manganitoferrites (Ln is a rare-earth element, and M II is an alkali-earth metal) were estimated by the developed method of calculation. Their standard entropies were calculated by the method of ionic increments, and their standard Gibbs energies of formation were determined by the Gibbs-Helmholtz equation.

The isobaric heat capacity of LaSrMnFeO5.5 ferrite is investigated within the temperature range of 298.15–673 K by a calorimetric method. On the curve of the dependence of the heat capacity on temperature, the λ-type effect is revealed relating to a phase transition of the second kind. Temperature dependencies of the thermodynamic functions S 0(T), H 0(T) -H 0(298.15), and Φ xx (T) are calculated. The temperature dependencies of permittivity and electrical resistance are studied within the temperature range of 303–493 K, and the results show that the composition under study has semiconductor properties.

The enthalpies of solution of 3-acetyl-9-methoxy-2-phenyl-11 H -indolizino[8,7- b ]indole and 8-acetylharmine in dimethyl sulfoxide were measured by isothermal calorimetry at solute: solvent molar ratios of 1: 9000, 1: 18000, and 1: 36000. From the data obtained, the standard enthalpies of solution of the compounds in dimethyl sulfoxide at infinite dilution were calculated. The heat capacities of 8-acetylharmine were determined by dynamic calorimetry in the interval 298.15–673 K, and the C p o = f ( T ) equations were obtained. The standard enthalpies of combustion of the compounds were estimated by approximate methods, and their heats of melting were calculated. From the data obtained, using Hess cycle, the standard enthalpies of formation of the compounds were calculated.

Калориметрическим методом в интервале 298.15–673 К исследована изобарная теплоемкость феррита LaSrMnFeO5.5. На кривой зависимостей теплоемкости от температуры выявлен -образный эффект, относящийся к фазовому переходу II рода. Вычислены температурные зависимости термодинамических функций S0(T), H0(T) – Н0(298.15) и хх(T). В интервале 303–493 К исследованы температурные зависимости диэлектрической проницаемости и электросопротивления, результаты которых показали, что данное соединение обладает полупроводниковыми свойствами.

The enthalpies of solution of cytisine derivatives (phosphoric acid cytiside dimethyl ester, cytisinovinyloxyethylaminothiourea) in 96% ethanol at various dilutions were determined by isothermal calorimetry. Equations describing the dependences Δ H s 0 = f ( m 1/2 ) ( m is the molal concentration) were obtained. The standard enthalpies of solution, combustion, melting, and formation (at 298.15 K) of the compounds were calculated.

The enthalpies of solution of a series of anthraquinone derivatives in dioxane at various dilutions were determined by isothermal calorimetry.

The enthalpies of solution of imidazolidine-2-thione and potassium isopropylxanthate in ethanol and their isobaric heat capacity in the range from 173 to (T m − 100) K were measured by calorimetry at 298.15 K. The standard enthalpies of formation, combustion, and melting of these compounds were estimated.