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Thermo-EMF, magnetothermo-EMF, magnetoresistance, and magnetization of single-crystal samples of Nd(1–x)Sr x MnO3 and Sm(1–x)Sr x MnO3 with 0 ≤ x ≤ 0.3 have been studied experimentally. A sharp increase in the thermo-EMF and giant magnetothermo-EMF and magnetoresistance has been observed near the Curie point T C in compounds with 0.15 ≤ x ≤ 0.3. At the same time, no peculiarities have been found in compositions with x = 0. Since compounds with x > 0 consist of ferromagnetic clusters of the ferron type that reside in an antiferromagnetic A-type matrix, this means that the sharp increase in the thermo-EMF near T C is caused by ferrons. Indeed, the disappearance of ferrons due to a magnetic field or heating above T C leads to an abrupt decrease in the thermo-EMF. Therefore, thermo-EMF in alloyed magnetic semiconductors has been determined by the impurity concentration and the sample volume.

Thermopower, magnetothermopower, resistivity, magnetoresistance, and magnetization of singlecrystalline samples of the Sm1–xSrxMnO3 system (x = 0.15, 0.2, 0.25, 0.3) have been experimentally studied. These compositions consist of ferromagnetic clusters of the ferron type dispersed in the A-type antiferromagnetic matrix. Colossal thermo- and negative magnetothermopower values reaching 94.5% in a composition with x = 0.3 in the region of Curie point TC in a magnetic field of 1.323 T. This result implies that thermopower is mostly related to ferron-type clusters, since their breakage under the action of magnetic field or heating above TC leads to a sharp decrease in thermopower values. These results imply that thermopower in doped manganite semiconductors is determined by the concentration of impurity and volume of a sample.

The thermopower, S, magnetothermopower, ΔS/S, resistivity, ρ, and magnetoresistivity, Δρ/ρ, depending on the temperature T and magnetic field H, have been studied in an Nd0.5Sr0.5MnO3 single crystal consisting of three types of clusters: an antiferromagnetic CE-type with charge-orbital ordering (below the Neel temperature TNCE ~ 145 K) and an A-type with TNA ~ 220 K; a ferromagnetic at 234 ≤ T ≤ 252 K, and a ferromagnetic metal phase below the Curie temperature TC = 248 K. The thermopower was found to be negative, indicating the dominance of the electronic type of conductivity. In the S(T) curves, a sharp minimum is observed in the temperature range of 100 K ≤ T ≤ 133 K, close to TNCE, where the absolute S value attains 53 μV/K. With a further increase in temperature, the absolute S value decreases rapidly; at 200 K it is equal to 7 μV/K. It then slightly increases, reaching its maximum value of 15 μV/K at a temperature of 254 K, which is close to TC. The absolute thermopower decreased under the influence of the magnetic field; i.e., a negative magnetothermopower occurs. In {ΔS/S}(T) curves, a sharp minimum is observed at T = 130 K close to TNCE, where the magnetothermopower reaches a huge value of ~45% at H = 13.23 kOe. A broad minimum in the {ΔS/S}(T) curves is observed near the Curie temperature and its value is also high, viz., ~15% in the maximum measuring magnetic field of 13.23 kOe. The extremely high magnetothermopower values mean that the charge-orbital ordered nanoclusters or ferron type make the main contribution to the thermopower of the entire sample. The behavior of the ρ(T) and {Δρ/ρ}(T) curves is similar to that of the S(T) and {ΔS/S}(T) dependencies, which is in agreement with this conclusion.

It was first shown that the thermoelectric power in a magnetic semiconductor Sm 0.55 Sr 0.45 MnO 3 is caused by ferromagnetic (FM) ferron-type nanoclusters and antiferromagnetic (AFM) CE-type nanoclusters with charge-orbital (CO) ordering. The presence of these clusters is caused by heavily Sr doping of a SmMnO 3 compound, which replaced Sm ions. Thermoelectric power S and magnetothermopower Δ S / S has been studied in three samples: ceramics and two single-crystal samples. One of single-crystals was cooled in the air, another one was cooled in an oxygen atmosphere. The annealing in oxygen closes oxygen vacancies and, thus, increases the fraction of the CE-type AFM phase with the CO ordering which displaces the oxygen ions. S ( T ) curves of single-crystal sample cooled in the air and ceramic sample have a sharp increase starting from Curie temperature ( T C ) region and a slow decline till 325 K. At the same time {Δ S / S }( T ) curves have a sharp minimum near T C =126 K, reaching the giant absolute value of 87% in the magnetic field H =14.17 kOe. This means that thermopower almost vanish with thermal destruction of FM clusters, i.e. thermopower is caused by these clusters in which crystal lattice is compressed. Oxygen cooled single-crystal's S ( T ) curves have a broad maximum near 270 K, including Neel temperature of CE-type clusters T NCE =240 K. {Δ S / S }( T ) curve has a sharp minimum at the T NCE reaching the absolute value of 50% in H =13.2 kOe. The decrease of S is caused by destruction of CO order displacing oxygen ions in CE-type AFM clusters. Thus changed crystal lattice in nanoclusters of ferron type or AFM of CE-type makes the main contribution in thermopower in these three samples.

Thermopower α and magnetothermopower ∆α/α were studied in the Sm0.55Sr0.45MnO3 samples, containing clusters of three types: ferromagnetic clusters with the Curie temperature TC = 126 K, A-type antiferromagnetic clusters with the Neel temperature TNA ≥ TC and CE-type antiferromagnetic clusters with the TNCE = 240 K. The curves of temperature dependence of α (T) have a large maximum including TC and TNCE and the sharp minimum on the {∆α/α}(T) curves in the TC-region. Negative magnetothermopower in minimum achieves the giant value ~ 85% in magnetic field 14.17 kOe. It is shown that thermopower is largely caused by the presence of ferromagnetic nanoclusters of ferron-type and to a lesser degree of CE-type antiferromagnetic clusters, in which there is a charge ordering, displacing oxygen ions.

The analysis of the IFN-status of healthy full-term neonatal infants and their healthy mothers with modern statistical methods was conducted. It was established that the IFN status of healthy full-term neonatal infants differs from the same of their mothers with higher occurrence of IFNs and strengthened induced production of IFNα/β and IFNγ. The statistically significant interaction between indicators of the IFN status of newborns and their mothers has been revealed. The obtained data is important for assessment of nonspecific resistance in system mother–newborn.

The thermopower α and magnetothermopower Δα/α have been studied on single-crystal Sm0.55Sr0.45MnO3 samples consisting of three types of magnetic clusters (ferromagnetic clusters with the Curie temperature TC = 134 K, the A-type antiferromagnetic clusters with the Neel temperature TNA ≥ TC, and the CE-type antiferromagnetic clusters with TNCE = 240 K). The temperature dependences of α and Δα/α have extremes in the vicinity of TNCE, namely, a wide maximum in curve α(T) and a sharp minimum in curve{Δα/α}(T). The negative magnetothermopower in the minimum has a giant value of 50% in the magnetic field of 13.2 kOe. The thermopower is shown to be mainly due to the existence of the CE-type antiferromagnetic clusters, in which there is a charge-orbital ordering that displaces the oxygen atoms. The changed crystal lattice inside these clusters changes the value of the thermopower inside them. This thermopower influences the voltage drop across the sample during measuring the thermopower and, thus, the effective value of α of the whole sample. The application of a magnetic field near TNCE accelerating the destruction of the CE-type antiferromagnetic order causes the sharp decrease in the thermopower of the whole sample. This implies that the CE-type antiferromagnetic clusters with the charge-orbital ordering make main contribution to the thermopower of the whole sample.

Thermopower α and magnetothermopower α/α were studied in the single-crystal Sm0.55Sr0.45MnO3 samples, containing clusters of three types: ferromagnetic clusters with the Curie temperature TC = 134 K, A-type antiferromagnetic clusters with the Neel temperature TNATC and CE-type antiferromagnetic clusters with the TNCE = 240 K. The curves of temperature dependence of α (T) and {α/α}(T) have extrema in the TNCE-region: large maximum on the first and sharp minimum on the second. Negative magnetothermopower in minimum achieves the giant value 50% in magnetic field 13,2 kOe. It is shown that thermopower is essentially caused by the presence of CE-type antiferromagnetic clusters, in which exists charge order, displacing oxygen ions

The researching of dependence of magnetization from temperature T and magnetic field in the Bi2Fe0.128Te2.844Se0.145 single-crystal showed that it have spinglass-like state with freezing temperature Tf= 40 K. Its electric resistance up to 100 K is ~ 103 Ohm and decreases with the temperature increase. At T > 110 K electric resistance ~ 10-2 Ohm and magnetization is four times smaller than in spinglass-like state. It can be assumed from these results that this sample is topological insulator at T > 110 K and at small temperature, where it is spinglass-like, offers the breaking of the time reversal symmetry.

Spontaneous generation of the electrical voltage in a Pr0.6Ca0.4MnO3 single crystal has been found. The charge and orbital ordering in the crystal takes place at T CO = 240 K, while the antiferromagnetic ordering occurs at T N = 174 K. As the temperature lowers, spontaneous voltage U increases initially slowly (in the temperature range from 300 K to T CO) and then more rapidly (in the range T CO-T N ). Starting from T N , the voltage U increases exponentially and, at 85 K, reaches 115 mV (in the ab plane) and 6.5 mV (along the c axis). The magnetic field differently affects the voltage U in different temperature ranges: it decreases the value of U in the temperature range of 85–130 K and increases in the range of 130–240 K. It is assumed that the spontaneous voltage is associated with the existence of ferromagnetic and charge orbital ordered clusters of different topologies in the crystal.

Spontaneous generation of electrical voltage U was found for the perovskite-like single crystal of Pr0.6Ca0.4MnO3, wherein the charge and orbital orderings occur at TCO = 240 K and the antiferromagnetic one occurs at the Neel point TN = 174 K. With decreasing the temperature, the U value increases first slowly (in the temperature range of 300 K-TCO) and then more rapidly (TCO-TN). Starting from TN, U increases exponentially and, at 85 K, reaches the value of 115 mV (in the ab plane) and 6.5 mV (along the c axis). The magnetic field has a different effect on the U value in different temperature ranges: in the temperature range of 85–130 K, it decreases U and, in the range of 130–240 K, increases U. The spontaneous voltage is thought to be caused by the existence of ferromagnetic and charge-orbital-ordered clusters of different topology in the sample. The latter clusters have own features and their structure are described by the non-centrosymmetric space group P21nm.

The analysis of high-precision ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}p\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}p$ cross-sectional data from the EPECUR Collaboration based on the multichannel $K$-matrix approach is presented. The sharp structures seen in these data are studied in terms of both opening thresholds and new resonance contributions. Some prominent features are found to be due to the opening $K\mathrm{\ensuremath{\Sigma}}$ channel. However, a complete description of the data is improved with the addition of two narrow resonant structures at $W\ensuremath{\sim}1.686$ and $W\ensuremath{\sim}1.720\phantom{\rule{4.pt}{0ex}}\mathrm{GeV}$. These structures are interpreted as manifestations of ${S}_{11}$ and ${P}_{11}$ resonances. The underlying nature of the observed phenomena is discussed.

The magnetocaloric effect (MCE) in La1 − xSrxMnO3, Sm0.55Sr0.45MnO3, and PrBaMn2O6 compounds is studied. The maximum values of MCE (ΔTmax) determined by a direct method in the second and third compositions and in La0.9Sr0.1MnO3 are found to be much lower than those calculated from the change of the magnetic part of entropy in the Curie temperature (TC) and the Neel temperature (TN) range. The negative contribution of the antiferromagnetic (AFM) part of a sample in the La1 − xSrxMnO3 system at 0.1 ≤ x ≤ 0.3 decreases ΔTmax and changes the ΔT(T) curve shape, shifting its maximum 20–40 K above TC. Lower values of ΔTmax are detected in the range TC = 130−142 K in polycrystalline and single-crystal Sm0.55Sr0.45MnO3 samples cooled in air. If such samples were cooled in an oxygen atmosphere (which restores broken Mn-O-Mn bonds and, thus, increases the volume of CE-type AFM clusters), the maximum in the temperature dependence of MCE is located at TN (243 K) for CE-type AFM clusters. A magnetic field applied to a sample during the MCE measurements transforms these clusters into a ferromagnetic (FM) state, and both types of clusters decompose at T = TN. The PrBaMn2O6 composition undergoes an AFM-FM transition at 231 K, and the temperature dependence of its MCE has a sharp minimum at T = 234 K, where MCE is negative, and a broad maximum covering TC. The absolute values of MCE at both extrema are several times lower than those calculated from the change in the magnetic entropy. These phenomena are explained by the presence of a magnetically heterogeneous FM-AFM state in these manganites.

In Sm0.55Sr0.45MnO3single crystals, grown by the floating-zone method with the cooling in oxygen, has been observed the spontaneous generation of voltage (SGV). Its maximum reaches 60 μV and occurs in the temperature range where simultaneous decay of the CE-type antiferromagnetic order and the charge order take place in some clusters. The SGV peak becomes lower by about 45% if magnetic field 14.2 kOe applied. Also we observed the SGV in La0.75Ba0.25MnO3single crystals. Maximum value of SGV occurs in a vicinity of the Curie temperature. The SGV value seems to be almost independent from the cooling or heating rate and crystallographic direction, but in La0.75Ba0.25MnO3it is smaller than in Sm0.55Sr0.45MnO3by an order of magnitude. La0.75Ba0.25MnO3compound contains ferromagnetic clusters, in which the electrical charges are localized according to gain in thes-dexchange energy. They are distributed in the paramagnetic lattice, impoverished of an electrical charge. It is shown that SGV stems from the presence of regions with different electrical charges in both samples.

Based on Mn-doped chalcopyrites CdGeAs 2 , ZnGeAs 2 and ZnSiAs 2 the new dilute magnetic semiconductors with p-type conductivity were produced. Magnetization, electrical resistivity, magnetoresistance and Hall effect of mentioned compositions were studied. Their curves of temperature dependence of magnetization have the similar form in spite of complicated character, for which the concentration and mobility of the charge carriers are responsible. Thus, for T T >15 K for a frustrated ferromagnetics. In compounds with Zn these two states dilute by spinglass-like state. This specific feature is assigned to an attraction of Mn ions occupying neighboring sites and to the competition between the carrier-mediated exchange and superexchange interactions. Curie temperatures of these compounds are above room temperature. These are the highest Curie temperatures in the A II B IV C V 2 :Mn systems.

Spontaneous generation of electric voltage has been found in a Sm0.55Sr0.45MnO3 single crystal grown by floating zone melting with cooling in oxygen. The maximum voltage of 60 μV has been observed in the region of temperatures corresponding, simultaneously, to destruction of the CE-type antiferromagnetic ordering and charge ordering in some clusters. The maximum voltage remains unchanged for 24 h and decreases by 45% in a magnetic field of 14.2 kOe. It has been shown that the spontaneous voltage is caused by the presence of regions with different electric charges in the sample.

The magnetocaloric effect ΔT has been studied by a direct method in two samples of the manganite Sm0.55Sr0.45MnO3, namely, a single crystal (sample A) and a ceramic sample (sample C). The temperature dependences of the ΔT effect of both samples exhibit a maximum at T max = 143.3 K for the sample A and T max = 143 K for the sample C. In these maxima, the values of the ΔT effect are 0.8 and 0.4 K in the magnetic field H = 14.2 kOe for the samples A and C, respectively. In addition, the ΔT(T) curve of the sample A has a minimum at T min = 120 K, in which ΔT = −0.1 K. The maximum value of the ΔT effect increases with an increase in the magnetic field H in the range of magnetic fields up to 14.2 kOe, and the rate of this increase at H > 8 kOe is higher than that at H < 8 kOe. These features of the ΔT effect are explained by the presence of ferromagnetic and antiferromagnetic A- and CE-type clusters in the samples.

New diluted magnetic semiconductors (CdGeAs2:Mn, ZnGeAs2: Mn, and ZnSiAs2: Mn chalcopyrites) were synthesized. Magnetization M, electrical resistivity, magnetoresistance, and the Hall effect of these compositions were examined. Although the M(T) curves are complicated, they are similar in shape, for which the concentration and mobility of the charge bearers. Their Curie points are higher than 300 K, the highest in systems of the AIIBIVC2V: Mn type.

A new p -type dilute magnetic semiconductor was synthesized on the basis of manganese-doped ZnSiAs 2 chalcopyrite. As the manganese percentage in ZnSiAs 2 increased, the Curie temperature increased from 325 to 337 K for compositions containing 1 and 2 wt % manganese. The ferromagnetic properties of the new dilute magnetic semiconductor were due to nanoclusters that were generated by concurrent substitution of manganese for elements in the cationic sublattice of chalcopyrite.

Based on Mn-doped chalcopyrite ZnSiAs2 the new dilute magnetic semiconductor with p-type conductivity was produced. The Curie temperature behavior of the produced semiconductor is distinctly dependent on the Mn concentration: 325 K for 1 wt.% and 337 K for 2 wt.% of Mn, consequently. Magnetization, electrical resistance, magnetic resistance and Hall effect of mentioned compositions were studied. Temperature dependence of magnetization M(T) have complicate behavior. For T  15 K the M(T) dependence is characteristic for superparamagnetic and at T > 15 K magnetization is sum of magnetizations of ensemble of superparamagnetic clusters and ferromagnetic phase contained frustration regions.

Definite regularity in the distribution of ferromagnetic, antiferromagnetic and superconducting elements is observed in the periodic table starting with the 4-th period. These trends were explained by distinction of degree of division of the d (f)- or р-orbitals of neighboring atoms in the crystal. We calculated also the radii of the external d (f)- and р-orbitals and the nearest to them orbitals with the Slater’s method. It is demonstrated that in the superconducting crystals the d-shells approach the nucleus of neighboring atoms are much closely those for ferromagnetic or antiferromagnetic crystals.

A new spintronics material with the Curie temperature above room temperature, the ZnSiAs2 chalcopyrite doped with 1 and 2 wt % Mn, is synthesized. The magnetization, electrical resistivity, magnetoresistance, and the Hall effect of these compositions are studied. The temperature dependence of the electrical resistivity follows a semiconducting pattern with an activation energy of 0.12–0.38 eV (in the temperature range 124 K ≤ T ≤ 263 K for both compositions). The hole mobility and concentration are 1.33, 2.13 cm2/V s and 2.2 × 1016, 8 × 1016 cm−3 at T = 293 K for the 1 and 2 wt % Mn compositions, respectively. The magnetoresistance of both compositions, including the region of the Curie point, does not exceed 0.4%. The temperature dependence of the magnetization M(T) of both compositions exhibits a complicated character; indeed, for T ≤ 15 K, it is characteristic of superparamagnets, while for T > 15 K, spontaneous magnetization appears which correspond to a decreased magnetic moment per formula unit as compared to that which would be observed upon complete ferromagnetic ordering of Mn2+ spins or antiferromagnetic ordering of spins of the Mn2+ and Mn3+ ions. Thus, for T > 15 K, it is a frustrated ferro- or ferrimagnet. It is found that, unlike the conventional superparamagnets, the cluster moment μc in these compositions depends on the magnetic field: ∼12000–20000μB for H = 0.1 kOe, ∼52–55μB for H = 11 kOe, and ∼8.6–11.0μB at H = 50 kOe for the compositions with 1 and 2 wt % Mn, respectively. The specific features of the magnetic properties are explained by the competition between the carrier-mediated exchange and superexchange interactions.

Bulk and film samples of manganese-doped zinc-silicon diarsenide are obtained. Investigation of electrical and magnetic properties of ZnSiAs2: Mn samples showed that they possess the combination of ferromagnetic and semiconductor properties at above room temperature and are of interest as materials for spin transport.

The experimental evidence of metamagnetism, giant negative magnetoresistance and spin glass state is presented for the compounds under study. An attempt is made to explain the jump-like phase transition of the colossal negative magnetoresistance of −4433% at 153.2 K into the colossal positive magnetoresistance of +980% at 154.2 K for the spinel sample with selenium. It was emphasized that in all the phenomena described in this paper the double exchange magnetic interaction plays the main role.

In this article is pointed out the particularly important role of the double exchange magnetic interaction in the appearance of the phenomenon of the coexistence of the negative giant magnetoresistance and the spin glass state in the selected RE-manganites and the spinels with chromium. To explain this phenomenon, its statistical background and the types of magnetic interactions in the compounds under study are taken into account. The particular importance of the double exchange magnetic interaction “cooperating” with the strong external magnetic induction results here from that: i. its coupling constant is several times greater than the superexchange one, ii. the spin orientation of the hopping electrons is conserved (always ferromagnetic coupling!) and the charge transfer makes the p-type metallic conductance.

We report here the preparation and properties of La 1 − x Ag y MnO 3 + δ thin epitaxial films. The original two-step preparation procedure was developed. At first, La 1 − x MnO 3 + δ were grown epitaxially by metal–organic chemical vapor deposition on the single-crystal substrates (001) and (110) SrTiO 3 , (001) LaAlO 3 , (111) and (001) ZrO 2 (Y 2 O 3 ). Treatment by the vapor of the metallic silver in the oxygen atmosphere (at 1 bar and 20 bar) was the second step resulting in the selective absorption of silver by La 1 − x MnO 3 + δ phase. The value of y depended on the process conditions and revealed different kinetics of the silver absorption for (001) and (110) orientation of La 1 − x MnO 3 + δ films. The films prepared were characterized by X-ray diffraction, scanning electron microscopy with energy-dispersion X-ray analysis, high resolution transmission electron microscopy, X-ray photoelectron spectroscopy, electrical resistivity and magnetoresistance measurements in a four-probe configuration. We have found that metal-insulator transition temperature ( T p ) in the series La 1 − x Ag x MnO 3 + δ possessed a maximum of 380 K at x = 0.15. Thus, T p of La 1 − x Ag x MnO 3 + δ films was significantly higher than ever reported in the literature for the La 1 − x Ag x MnO 3 + δ ceramics. La 1 − x Ag x MnO 3 + δ films demonstrated the important role of the ferromagnetic fluctuations above Curie temperature T c resulting in the sign change of the resistivity curve temperature slope d R / d T and a significant shift of T p well above T c . The maximum of the magnetoresistance on the temperature scale was close to d R / d T maximum. The intrinsic magnetoresistance values as high as 22% at 310 K and 50% at 280 K were measured in the magnetic field of 1 T in the series of La 1 − x Ag y MnO 3 + δ epitaxial films.

Germanium zinc diarsenide crystals with various manganese fractions, (ZnGeMn)As2, were prepared by reacting high-purity powders of zinc diarsenide, germanium, arsenic, and manganese. The manganese solubility at temperatures near the ZnGeAs2 melting temperature was 3.5 wt % as determined by X-ray fluorescence analysis. The unit cell volume decreased with rising manganese concentration. Magnetization in fields up to 50 kOe, magnetic susceptibility, electrical resistance, and Hall constants were measured over wide temperature ranges. Manganese-doped samples had spontaneous magnetization and high Curie temperatures reaching 367 K. Their magnetic properties are characteristic of spin glasses in low magnetic fields. In higher fields, the spin state changed to spontaneous magnetization.

Basic tendencies in the distribution of ferromagnetic (FM), antiferromagnetic (AFM) and superconductive (SC) elements in the periodic table D.I. Mendeleev are traced. FM is observed at the elements in which 3d-shell is more than half-filled (the number of 3d-electrons 6 ⩽ n ⩽ 8 ), and at the elements with 4f-shell, contained k electrons in 4f-shell, at which the sum k + n ⩾ 8 . Estimation of the radii of the d-, f- and p-orbitals on Slater method shown that 3d- and 4f-shells of FM are more pressing, than the ones with smaller n and k + n , and are well separated in crystal. AFM is observed at the elements, at which 3d- or 4f-shells are precisely half-filled. SC is observed in the 3d-, 4d- and 5d-elements at 1 ⩽ n ⩽ x , x grows from 3 in 3d-elements to 7 in 4d- and 5d-elements, and in 7th period only at n = 2 and k + n = 3 . Further, SC is observed at the elements, at which 3p-, 4p-, 5p- and 6p-shells contain no more than 4 electrons. In SC crystals the wave functions of external d- and p-electrons of each atom penetrate inside neighbor atoms and overlap with corresponding wave functions with smaller main quantum number than of central atom. In this case the separation of spin and charge in electron is quite possible and the charges without spin become bosons. Spins obtained magnetic moments are ordered antiparallel by two. At transfer that pair in the parallel state by magnetic field its magnetic flux from magnetic field component along of magnetic field is equal to 1 fluxon (quant of magnetic flux).

Doping of the ZnGeAs2 semiconductor with manganese has produced compositions with spontaneous magnetization and high Curie temperatures of up to 367 K for the composition 3.5 wt% Mn. Their magnetic properties are characteristic of spin glasses at temperatures T < T S and magnetic fields H < 11 kOe. In stronger fields, the spin glass state transforms into a phase with a spontaneous magnetization 4–5 times weaker than that to be expected under ferromagnetic ordering of all Mn ions. This is obviously a singly-connected ferromagnetic phase containing regions with frustrated bonds. The frustrated regions and the spin glass phase have inclusions of noninteracting ferromagnetic clusters, because these regions and the spin glass phase at low temperatures exhibit a strong increase in the magnetization M, with the dependence M(T) being described by the Langevin function. Measurements of the electrical resistivity ρ and the Hall effect have revealed that, for T < 30 K, the resistivity ρ of compositions with 1.5 and 3.5 wt % Mn is higher that at 30 K, which makes superexchange dominant and gives rise to the onset of the spin glass state. The nonuniform distribution of Mn ions in the spin glass phase accounts for the existence of isolated ferromagnetic clusters, their ferromagnetism being generated by carrier-mediated exchange. As the temperature increases still more, the increase in the mobility occurs faster than the decrease in the concentration, thus promoting an enhancement of the carrier-mediated exchange and growth of the ferromagnetic clusters in size, which at T = T S come in contact. This signifies a transition from a multiply-to a singly-connected ferromagnetic phase, which contains microregions with frustrated bonds.

Giant volume magnetostriction, reached ∼6×10 −4 in magnetic field 8.2 kOe, is found in La 1− x M x MnO 3 (M=Ba, Sr, Ca, Ag) manganites near Curie-point T C . Volume magnetostriction ω and magnetoresistance exhibit similar dependence on temperature and magnetic field in T C region that is explained by the presence in these compounds of magnetic two-phase ferromagnetic–antiferromagnetic state due to strong s−d and/or d−d exchange. Maximum | ω |-value depends from radius of M-cation: it is larger the larger the difference | R A − R La3+ | and A-cation size variance σ 2 , where A=La 1− x M x .

Motto The first address of Satan to the human race began most modestly with the word: why? Adam Mickiewicz (1798–1855) The resistance, magnetoresistance and magnetization measurements have been performed in the temperature range of 4.2–300 K and in the external magnetic inductions up to 14 T for the Sm1− x Sr x MnO3 (x = 0.33, 0.45) and RE0.55Sr0.45MnO3 (RE0.55 = Eu0.397Nd0.153, Tb0.25Nd0.30) manganites. In these samples the metal–semiconductor phase transitions as well as two kinds of the magnetic phase transitions the ferromagnetic–paramagnetic and metamagnetic (both spin-flip and spin-flop) have been observed. It was found that correlations between the magnetic and electrical phase transitions appear at high values of the external magnetic inductions. These correlations consist, simultaneously, of the large negative magnetoresistance and metamagnetic phase transitions. The existence and reconstruction of the ferromagnetic and antiferromagnetic clusters under the influence of the external magnetic induc...

We present the first measurements of the double spin asymmetries A N N and A S S at s = 200 GeV , obtained by the PP2PP experiment using polarized proton beams at the Relativistic Heavy Ion Collider (RHIC). The data were collected in the four momentum transfer t range 0.01 ⩽ | t | ⩽ 0.03 ( GeV / c ) 2 . The measured asymmetries, which are consistent with zero, allow us to estimate upper limits on the double helicity-flip amplitudes ϕ 2 and ϕ 4 at small | t | as well as on the difference Δ σ T between the total cross sections for transversely polarized protons with antiparallel or parallel spin orientations.

Giant volume magnetostriction (GVM) is detected near the Curie temperature T C in La1−x AxMnO3 single crystals (A = Ca, Sr, Ba, 0.1 ≤ x ≤ 0.3) and above T C in La1−x AgyMnO3 (x = y = 0.15, 0.2 and x = 0.2, y = 0.1) ceramics (in the latter system, giant volume magnetostriction attains a value of 6.5 × 10−4 in a magnetic field of 8.2 kOe). The behavior of GVM and colossal magnetoresistance (CMR) is found to be the same: both quantities have negative values, the temperature dependences of their absolute values pass through a peak, and the isotherms do not exhibit saturation up to the maximal measuring fields of 130 kOe. In compounds with compositions La0.7Ba0.3MnO3 and La0.85Ag0.15MnO3, GVM and CMR were observed at room temperatures (in a magnetic field of 8.2 kOe, GVM attains values of 2.54 × 10−4 and 2 × 10−4 and CMR is equal to 11.6 and 11.2%, respectively). Both phenomena are attributed to the presence of a magnetic (ferromagnetic-antiferromagnetic) two-phase state in these systems, which is associated with a strong s-d exchange. It is found that the maximum value of the GVM in single crystals of La1−x AxMnO3 (A = Ba, Sr, Ca, Ag) depends on the radius R A of cation A (it is the higher, the larger the difference $$|R_A - R_{LA^{3 + } } |$$ ). The only exception is the compound with A = Ag, in which the pattern is complicated by additional defectiveness. Local disorder in the La1−x Ax sublattice, which is associated with the presence of cations with different radii, leads to a displacement of oxygen ions and to crystal lattice softening. The exchange s-d interactions in La1−x AxMnO3 (A = Ca, Sr, Ba, Ag) are found to be comparable with electrostatic interactions ensuring the existence of the crystal; this facilitates manifestation of the GVM.

We have established conditions for the preparation of CuGaTe2〈Mn〉 chalcopyrite solid solutions containing manganese on one or two cation sites, which are expected to be suitable for spintronic applications. Models for the formation of the solid solutions have been proposed, and the cation and valence distributions have been inferred from experimental data. The magnetic and electrical properties of CuGaTe2〈Mn〉 can be accounted for by the presence of Mn2+-containing superparamagnetic clusters.

Solid solutions Cd1−x MnxGeP2 (x=0−0.19) have been synthesized and identified. In these solutions, the unit cell parameters decrease with an increase in the manganese content. The solid solution Cd0.81Mn0.19GeP2 is a ferromagnet with the Curie temperature T C ≈ 311 K. The paramagnetic moment of Mn2+ ions equal to 5.8 μB, as well as the spontaneous magnetization constituting 76% of the total magnetization of a crystal, has been determined with the use of the Langevin function. The origin of ferromagnetism in CdGeP2:Mn is exchange mediated by charge carriers (holes). These holes are caused by cationic defects in the structure of chalcopyrite.

In single-crystal La0.7Ba0.3MnO3, giant volume magnetostriction was observed for the first time to reach 2.54 × 10−4 at room temperature and a still larger level of 4 × 10−4 at the Curie point T C = 310 K in a magnetic field of 8.2 kOe. At the same temperatures and magnetic field, this effect is complemented by a colossal magnetoresistance of 15.2 and 22.7%, respectively. The volume magnetostriction ω and magnetoresistance Δρ/ρ follow similar patterns in the proximity of T C; namely, ω and Δρ/ρ are negative, maxima are observed in the |ω|(T) and |Δρ/ρ|(T) curves, and the ω and Δρ/ρ isotherms do not saturate in the highest fields applied. These phenomena are assigned to the fact that, in the above composition, there exists a two-phase magnetic (ferromagnetic-antiferromagnetic) state induced by strong s–d exchange.

We report on the first measurement of the single spin analyzing power ( A N ) at s = 200 GeV , obtained by the PP2PP experiment using polarized proton beams at the Relativistic Heavy Ion Collider (RHIC). Data points were measured in the four momentum transfer t range 0.01 ⩽ | t | ⩽ 0.03 ( GeV / c ) 2 . Our result, averaged over the whole | t | interval is about one standard deviation above the calculation, which uses interference between electromagnetic spin-flip amplitude and hadronic non-flip amplitude, the source of A N . The difference could be explained by an additional contribution of a hadronic spin-flip amplitude to A N .

The functional property of interferon status was studied in 22 mothers and their full-term infants infected with Herpes Simplex Virus and Cytomegalovirus. The findings showed the necessity of interferon status definition in full-term infant for solving the questions about using interferon agent in the complex treatment of viral disease.

The X-ray absorption K-edges of sulfur in CuCr2−xSbxS4 (x = 0.3, 0.4, 0.5) have been measured and compared to linearized augmented plain wave (LAPW) numerical calculations. The near edge region is generated by magnetically polarized and hybridized S 2p energy levels and shows small change with increased Sb content, which can be attributed to the movement of Cr 3d spin-down states up on the energy scale. The LAPW result confirms this effect. Moreover, the calculations show that the antimony in those spinels is rather in +3 than in +5 valence state. The calculated magnetic moment on Cr equals to 2.72μB. In EXAFS, there is no visible change between x = 0.3 and 0.5 spectra, which indicates that the local structure does not change significantly.

Ferromagnetism is found in the CdGeAs 2 chalcopyrite doped by Mn. The Curie point of these materials achieves 355 K that is the highest one in A II B IV C V 2 :Mn systems. These systems are heterogeneous magnets and they consist of ferromagnetic and superparamagnetic phases. The volume of the first phase increases with a level of doping. An origin of ferromagnetism in CdGeAs 2 :Mn can be related to the existence of vacancies in (Cd, V C , Mn) GeAs 2 or non-stoichiometry of (Cd, Ge, Mn) GeAs 2 .

A program of measurement of the polarization parameter P in elastic {pi}{sup +}p interaction in the resonance region of backward pion scattering is presented. This program is aimed at determining the bifurcation points of the trajectory of zeros of the pion-nucleon amplitude and, hence, at unambiguously reconstructing the amplitude of {pi}N scattering in the second resonance region. It is planned to perform a relevant experiment in a pion beam from the accelerator of the Institute of Experimental and Theoretical Physics (ITEP, Moscow)

Our experiments on the preparation of the composites of CMR manganites and metal silver have shown that in the case of La 1− x MnO 3+ δ the vacancies in the A-sublattice of the perovskite structure can be filled by Ag + ions under the soft conditions of the synthesis. Neutron diffraction refinement of La 0.8 Ag 0.2 MnO 3.00 clearly proves the silver doping in the A-sublattice. Depending on P (O 2 )– T synthesis conditions the solid solutions with the broad stoichiometry range La 1− x Ag y MnO 3+ δ (0.3 ≥ x ≥ y ) were prepared. We report here the evolution of the oxygen stoichiometry, the crystal structure as well as electro-physical properties in the series of the solid solutions. Curie temperature comes over a maximum exceeding the room temperature with the increase of silver content. La 1− x Ag y MnO 3+ δ solid solutions can be useful for the construction of the room temperature magnetic field sensors based on the magnetoresistance effect.

Giant volume magnetostriction at room temperature is found for the first time in a La(0.7)Ba(0.3)MnO(3) single crystal, achieving 2.54 × 10(-4) in a magnetic field of 8.2 kOe. An even greater value of the volume magnetostriction, equal to 4 × 10(-4) in the same magnetic field, is observed at the Curie point T(C) = 310 K.Volume magnetostriction and magnetoresistance exhibit similar dependences on temperature and magnetic field in the T(C)-region, that is explained by the presence in this compound of a magnetic two-phase ferromagnetic-antiferromagnetic state due to strong s-d exchange.

Ferromagnetism is found in the CdGeAs2 chalcopyrite doped by Mn. The Curie point of these materials achieves 355 K. This is the highest Curie point in AIIBIVCV2:Mn systems. These are heterogeneous magnets, they consist of a ferromagnetic and superparamagnetic phases. Portion of first phase increases with a level of doping. An origin of ferromagnetism in CdGeAs2:Mn is connected with the existence of vacancies (Cd, VC, Mn)GeAs2 or non-stoichiometric (Cd, Ge, Mn)GeAs2, as only in this case the ferromagnetic state is more advantageous than a spin glass-like state on theoretical estimations. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The PP2PP experiment is one of five experiments at the Relativistic Heavy Ion Collider (RHIC) at the Brookhaven National Laboratory, Long Island, New York. It is designed to measure the elastic scattering of protons at s = 50–500 GeV. The detector consists of silicon strip detectors mounted in Roman Pots and installed in the RHIC ring 60 m from the interaction region. During the engineering run of 2002 and physics run of 2003 the detectors were inserted as close as 15 mm from the proton beam. An overview of the experiment and details of the detector design and performance will be presented.

The SPIN-P experimental setup was designed for measuring the P asymmetry during pion scattering into the backward hemisphere at a minimum differential cross section of elastic πpscattering. The physical grounds of the experiment and the results of its simulation by the Monte Carlo method are presented. The setup is composed of a polarized proton target in a superconducting solenoid with vertical polarization of free protons, wire track detectors, scintillation counters, electronics for data readout and processing, and an appropriate computer network. The experimental program has been under way since 2002 on the pion beam of the proton synchrotron at the Institute of Theoretical and Experimental Physics (Moscow).

A doped manganite with the composition Eu0.55Sr0.45MnO3 exhibits giant negative magnetostriction and colossal negative magnetoresistance at temperatures in the vicinity of the magnetic phase transformation (T∼41 K). In the temperature interval 4.2 K≤T ≤40 K, the isotherms of magnetization, volume magnetostriction, and resistivity exhibit jumps at the critical field strength H c1, which decreases with increasing temperature. At 70 K ≤T ≤120 K, the jumps on the isotherms are retained, but the shapes of these curves change and the H c1 value increases with the temperature. At HH c1, the magnetoresistance becomes negative, passes through a minimum near 41 K and then reaches a colossal value. The observed behavior is explained by the existence of three phases in Eu0.55Sr0.45MnO3, including a ferromagnetic (in which the charge carriers concentrate due to a gain in the s-d exchange energy) and two antiferromagnetic phases (of the A and CE types). The volumes of these phases at low temperatures are evaluated. It is shown that the colossal magnetoresistance and the giant volume magnetostriction are related to the ferromagnetic phase formed as a result of the magnetic-field-induced transition of the CE-type antiferromagnetic phase to the ferromagnetic state.