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Mesoporous CoFe2O4 nanowires (NWs) were prepared with ordered mesoporous SBA-15 silica, and then were used to activate peroxymonosulfate (PMS) to degrade ciprofloxacin (CIP). All results showed that mesoporous CoFe2O4 NWs efficiently activated PMS and greatly improved the degradation of CIP in aqueous solution. The influence of PMS and CoFe2O4 on the CIP removal was taken into accounted, which indicated that the dominant sulfate radicals for the CIP degradation. Mesoporous-structure of CoFe2O4 NWs could absorb CIP and PMS in high concentration near CoFe2O4 NWs and promoted this degradation. The 100 ml CIP (20 mg/L) could be completely removal in the optimum conditions with 2 mM PMS and 0.3 g/L S-130, and the CIP removal presented the excellent recyclability with the CIP degradation as high as about 93% after four consecutive cycles. Owing to the high efficiency, excellent magnetic respond and good reusability, mesoporous-structured CoFe2O4 NWs could be regarded as the promising heterogeneous catalysts for PMS to degrade CIP.

The isotropic nanoparticles (NPs) and anisotropic bulk samples of MnBi were prepared from Mn NPs by using zero-field and field-assisted reactive sintering, respectively. The MnBi NPs are irregular in shape with size d

One-dimensional nickel (Ni) microwires were synthesized by the magnetic-field-induced (MFI) microemulsion-hydrothermal method using Ni nanospheres as seeds. The influence of the chemical conditions and magnetic field on the morphology and magnetic properties of Ni microwires were investigated by X-Ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometry (VSM). The strength of magnetic field greatly affected the morphology and magnetic properties of Ni microwires. The growth and morphology of Ni microwires depended on the competition between Brownian motion and magnetic dipole moments from magnetic field. The larger nanoparticles with the higher magnetic moments preferred to form one-dimensional Ni microwires and their length increased up to several millimeters with the increasing magnetic field strength, while the average diameter of Ni microwires decreased. Furthermore, the easy magnetization direction of Ni microwires was parallel to the direction of magnetic field and the Ni microwires axis.

The effect second milling time on the electromagnetic properties of MnZn ferrites has been studied up to MHz range. The average particle sizes of powder ranging from 1.49 to 1.16 μm were obtained by varying the second milling time from 72 to 324min. It is found that the total losses (Pcv) deteriorate when the second milling time over 252 min and the limit particle size is 1.21 μm. The value of initial permeability (μi) reduces by 20% when the particle size is 1.16 μm due to the uneven distribution of grain size, indicating that uniform microstructure demands suitable particle size. Meanwhile, the eddy current loss (Pe) and residual loss (Pr) dominate the total loss at 3 MHz playing a significant role in total losses. The hysteresis loss (Ph) and eddy current loss (Pe) deteriorate gradually at 3 MHz when the particle size is 1.21 μm at 100 °C. The residual loss increases greatly with the particle size decreasing at 3 MHz. An excellent MnZn power ferrite possessing high initial permeability (μi = 887), high saturation magnetic flux density (Bs = 531 mT) and low total losses (Pcv = 1940 kW/m3) at 3 MHz-50 mT is synthesized in this research.

Mesoporous indium (In)-doped hematite (α-Fe 2 O 3 ) nanowires were synthesized with mesoporous SBA-15 silica as a hard template, and then the influence of In dopant on the microstructure and gas-sensing performance was investigated in detail. With characterization by transmission electron microscopy, X-ray diffraction, UV–vis spectroscopy, and nitrogen physisorption experiments, it was shown that the average grain size increased for up to 1 mol% In dopant and then decreased with increasing In dopant content, while the surface area changed in the inverse manner. Because of the low melting point of In, In acted as a fluxing agent and entered the α-Fe 2 O 3 lattice when the In content was low, and the average grain size increased. With higher In content, In precipitated out the lattice and existed at the grain boundary, and the grain size decreased. It is concluded that In in the lattice increased lattice distortion and In at the boundary increased the surface area and oxygen vacancies, which were both beneficial for improving the gas-sensing performance. The response of In-doped α-Fe 2 O 3 nanowires increased by about 30%–50% as compared with that of pure α-Fe 2 O 3 nanowires. The gas sensor based on 3 mol% In–doped α-Fe 2 O 3 nanowires exhibited the best gas response and a rapid response-recovery time toward ethanol at the optimum temperature. Owing to the same valence, In dopant affected only the microstructure and components of the α-Fe 2 O 3 lattice, which was necessary to improve the gas-sensing behavior.

Mesoporous Co3O4 nanowires were synthesized with the nanocasting method, and then the dispersed Co 3O4 nanowires (Co3O4-DNWs) were separated from the bundled Co3O4 nanowires (Co3O4-BNWs) by the centrifugation technique. From the characterization with TEM, X-ray diffraction, UV–vis spectra and nitrogen adsorption-desorption isotherm, both samples present the same mesoporous-structure, diameter and the similar defects due to the same synthesis conditions. All results indicate that the microstructures and morphology of Co3O4 nanowires greatly affect the toluene gas sensing performance. Owing to the mesoporous-structures with the high surface area, the sensitivities of both samples are higher than others’. Co3O4-DNWs exhibit the higher specific surface area (44.98 m2 g−1) than Co3O4-BNWs, leading to the excellent gas-sensing properties to toluene gas at the optimized operating temperature of 210℃. Moreover, both samples present the excellent stability and selectivity to toluene gas. The gas-sensing mechanism results from the surface oxygen and toluene gas adsorption through comparing the sensitivity of Co3O4-DNWs and Co3O4-BNWs.

Porous perovskite lanthanum ferrites (LaFeO3) powders were synthesized under the different pH value by sol-gel technique and self-propagating combustion method. After the characterization with XRD, SEM, VSM, nitrogen adsorption-desorption isotherm and UV–Vis spectroscopy, the magnetic properties, photocatalytic activity and gas-sensing performance are discussed in detail. All LaFeO3 samples exhibit ferromagnetism for the spin mismatch due to oxygen vacancies. LaFeO3 powders present the good photocatalytic performance to MB and could be easily separated by magnetic separation technique after photocatalysis. Furthermore, the LaFeO3 gas sensors exhibited the considerable sensitivity to ethanol gas. Among all samples, LF-1 (LaFeO3 powders prepared at pH = 1) present the highest removal rate of MB (68%), the largest saturation magnetization (4.57 emu/g) and the best gas response to ethanol. The highest response for LF-1 sensor reaches (263.4) at the optimized operating temperature of 250 °C to 100 ppm ethanol gas, which should be attributed to the higher oxygen vacancies.

The mesoporous α-Fe 2 O 3 nanowires (NWs) were successfully synthesized by changing the calcination temperature from 550 to 750 °C (marked NWs-550, NWs-650 and NWs-750) via using SBA-15 silica as the hard templates with the nanocasting method. The characterization results indicated that the bandgap of the as-prepared samples hardly changed and the high BET surface areas changed a little with the calcination temperature from 550 to 750 °C. Mesoporous α-Fe 2 O 3 NWs had been found to possess the remarkable gas-sensing performance to ethanol gas. The gas-sensing behavior indicated that α-Fe 2 O 3 NWs-650 exhibited the higher response than that of α-Fe 2 O 3 NWs-550 and α-Fe 2 O 3 NWs-750. The calcination-temperature-dependent gas-sensing properties were mainly attributed to the competition of surface defects and body defects by the crystallization temperature. The lower calcination temperature could create more surface defects to improve the gas-sensing response, while the higher temperature would reduce the body defect and make the charge carriers transport easily. As the result, the suitable calcination temperature was desired to optimize the defects of nanostructures to improve the gas sensitivity.

Ultra-high purity CrO 2 was prepared by decomposing CrO 3 in O 2 with gas pressures up to 40 MPa, which were maintained throughout the decomposition process of CrO 3 to prevent the formation of any other phases of chromium oxides. Our method is different from the traditional methods that start from or under ambient pressures. The high oxygen pressure makes the meta-stable CrO 2 stable from the initial stage of preparation. As a result, the purity of the as-prepared CrO 2 is improved, and this has been further proved by the highest magnetization of the samples. The as-prepared CrO 2 particles show very large grains with flat surfaces, octagonal cross-section, and straight edges, owing to the high mobility of Cr ions in CrO 2 at temperatures above its melting point. The lattice parameters of CrO 2 are a = 4.4176 A and c = 2.9144 A. The maximum value of the magnetic entropy change of the high purity CrO 2 particles is ∼2.83 J/kg·K for an applied field of 1.5 T. The preparation of pure CrO 2 is important for studying its intrinsic properties and for applications in spintronic devices.

Mesoporous bundled NiFe 2 O 4 nanowires were synthesized using mesoporous silica SBA-15 as hard template, and then NiO nanoparticles were implanted into NiFe 2 O 4 nanowires to prepare ordered NiO/NiFe 2 O 4 nanocomposites. X-ray diffraction, N 2 adsorption-desorption, transmission electron microscopy and energy dispersive spectrometer were used to characterize the microstructure of the as-prepared samples. All results indicated that mesoporous NiFe 2 O 4 nanowires presented in bundle with the pore-volume percent of about 42% and NiO nanoparticles existed in the mesopores. The magnetic behavior of NiFe 2 O 4 nanowires and NiO/NiFe 2 O 4 nanocomposites were investigated with superconducting quantum interference device, and the saturation magnetization decreased with the increasing NiO content, while the coercivity and exchange bias field increased. The exchange bias effect was obviously observed for the NiO/NiFe 2 O 4 nanocomposites at low temperature and increased with the NiO content. It's concluded that interfaces magnetic interactions and surface energy barrier of NiO nanoparticles greatly affected the magnetic behavior of the NiO/NiFe 2 O 4 nanocomposites.

Mesoporous n-type hematite bunched nanowires (α-Fe2O3 BNWs) and Zn-, In- and Sn-doped α-Fe2O3 BNWs were synthesized by nanocasting method, and then the influence of the different-valence metals-doping on the microstructures, components and gas-sensing properties is discussed in detail. All samples present mesoporous-structure and are composed of the uniform α-Fe2O3 nanowires. The Zn, Fe, Sn and In-doped concentration decreased with the increasing radius of their hydrated ions. The ethanol gas-sensing results indicate that the different-valence metals-doping greatly affects the response of α-Fe2O3 BNWs sensors to ethanol gas. The sensitivity to 100 ppm ethanol gas increased from 10.046 for Fe1.896Zn0.104O2.948 BNWs sensor up to 45.556 for Fe1.938Sn0.062O3.031 BNWs sensor with the increasing metal valence. The high-valence Sn-doping not only decreases the ground state resistance, but also reduces barrier and work function of α-Fe2O3 BNWs, which results in the improved the sensitivity of α-Fe2O3 BNWs.

Photocatalytic Bi2WO6 and magnetic Fe3O4 nanoparticles were synthesized with hydrothermal process, and then were bonded together with polyethylene glycol and oxidized to form Fe3O4/Bi2WO6 and γ-Fe2O3/Bi2WO6 nanocomposites. The microstructure, component, magnetic response and photocatalytic degradation to ciprofloxacin (CIP) were studied with x-ray diffraction, N2 adsorption-desorption isotherms, energy dispersive spectrometer, vibrating sample magnetometer and UV/Vis spectrophotometer. Bi2WO6 nanoparticles presented the highest CIP removal of about 98% in 120 min under visible light irradiation, which was higher than that of Fe3O4/Bi2WO6 (90%) and γ-Fe2O3/Bi2WO6 (65%) nanocomposites. Both Bi2WO6-based nanocomposites could be easily separated by external magnetic field in 1 min. Fe3O4/Bi2WO6 nanocomposites showed the better synergistic effect of magnetic response and photocatalytic performance under visible light irradiation. Moreover, the photocatalytic mechanism for magnetic nanocomposites was deduced based on the energy band theory of semiconductor heterojunction contact.

A facile and easily reproducible laser ablation method has been developed to synthesize high quality Mn3O4 nanoparticles from Mn pieces in ambient air. By changing the laser ablation air pressure to ~20 Pa, a mixture of α-Mn and Mn3O4 composite nanoparticles were obtained. Most of the Mn3O4 nanoparticles are spherical in shape size ranging from 20 to 90 nm. Besides spherical shape, a considerable amount of α-Mn/Mn3O4 nanoparticles show irregular shape and aggregation. The oxide nanoparticles exhibit large coercivity up to 1.05 T, which is almost four times to that of the Mn3O4 single crystals, owing to size effect. The coercivity was further enhanced to 1.17 T in α-Mn/Mn3O4 nanoparticles, owing to the additional interfacial effect between α-Mn and Mn3O4 besides size effect. The presence of the antiferromagnetic/ferrimagnetic α-Mn/Mn3O4 interface results in an exchange bias field up to ~65 mT in the nanoparticles.

The characteristics of nat .,7 LiF:Mg,Cu,P thermoluminescent detectors exposed to high-energy 12 C (165 MeV/nucleon) ions and 60 Co γ -rays have been investigated. Through a careful analysis of the glow curves by the GlowFit program, it is found that the relative amplitude of satellite peaks 3, 5, 6 and 7 to peak 4, measured after irradiated with high-energy 12 C ions, is higher than that with 60 Co γ -rays for both types of TL detectors. It is observed that nat .,7 LiF:Mg,Cu,P thermoluminescent detectors would also exhibit a good linear dose response when the delivered dose of high-energy 12 C ions is in the range from 100 mGy to 1600 mGy. Furthermore, the relative efficiency of the nat .,7 LiF:Mg,Cu,P thermoluminescent detectors is independent of the absorbed dose in the linear dose response range. Compared to previously published data, the relative efficiency of the 7 LiF:Mg,Cu,P TL detectors decreases with increasing LET values.

The neutron yield from thick target of Pb irradiated with 250 MeV protons has been studied experimentally. The neutron production was measured with the water-bath gold method. The thermal neutron distributions in the water were determined according to the measured activities of Au foils. Corresponding results calculated with the Monte Carlo code MCNPX were compared with the experimental data. It was found out that the Au foils with cadmium cover significantly changed the spacial distribution of the thermal neutron field. The corrected neutron yield was deduced to be 2.23 +/- 0.19 n/proton by considering the influence of the Cd cover on the thermal neutron flux. (C) 2014 Elsevier B.V. All rights reserved.

The magnetic Co3O4 nanowires were synthesized using the templates of SBA-15, and then the well-dispersed nanowires (D-wires) were separated from the bundled ordered nanowires (B-wires) with the centrifugal technique. TEM images indicated that D-wires were highly dispersed Co3O4 nanowires and B-wires existed in bundles. All samples possessed the antiferromagnetism and superparamagnetism at high temperature. After revealing the intrinsic magnetic properties of Co3O4 nanowires with D-wires, the magnetic behavior of B-wires was discussed in detail, and then the magnetic interaction between neighboring nanowires could be deduced. The exchange bias effect from the body Co3O4 antiferromagnetism and surface ferromagnetism was observed at low temperature. The magnetization of B-wires was higher than that of D-wires, which was attributed to the constraint of the surface spin coupling between the neighboring nanowires to the surface affect of nanostructures.

The magnetic properties and magnetocaloric effect have been studied in Pr0.5Sr0.5−xLixMnO3 (0≤x≤0.3) prepared by conventional solid-state reaction. Magnetic measurements versus temperature revealed that the Curie temperature (TC) increased gradually with increasing lithium content (0.05≤x≤0.2); TC values are about 260 and 290 K for x=0.05 and 0.2, respectively. But it shows abrupt drop in TC value for x=0.3 (TC=235 K). Meanwhile, the paramagnetic–ferromagnetic (PM–FM) transition is second-order in x≤0.2, it changes into first order for x=0.3. However, the magnitude of the isothermal magnetic entropy (ΔSM) increased gradually. In a magnetic field change of 15.0 kOe, the maximum ΔSM achieved around TC are −1.03, −1.05, −1.48, −2.17 and −2.64 J kg−1 K−1 for x=0, 0.05, 0.1, 0.2and 0.3, respectively. Although ΔSM for x=0.2 is smaller compared to the composition x=0.3, the relative cooling capacity (RCP) 59.6 J kg−1 is similar compared with the value 59.8 J kg−1 for x=0.3. Addition of suitable TC makes it a desirable material for room temperature magnetic refrigeration.

In this paper, the magnetic properties and magnetocaloric effect in La0.7Sr0.3Mn1−xCoxO3 prepared by conventional solid state reaction have been studied. The samples have rhombohedra crystal structure as was determined by room temperature X-ray diffraction. From the measurements, it was found that the Curie temperature (TC) and magnetic entropy change (ΔSM) are strongly dependent on the Co content. The Curie temperature was found to be 338, 300 and 260 K for x=0, 0.05 and 0.1, respectively. Although the variation of maximum entropy change shows a similar tendency with TC, the phase transition temperatures were widened and the |ΔSM|max values, under a change of the magnetic field of 15 kOe, amount to −1.36, −1.17 and −0.92 J/kg K for x=0, 0.05 and 0.1, respectively. The results suggest that Mn-site substitution should be used to tailor Curie temperature and achieve large relative cooling power (RCP).

The influence of monovalent doping on the magnetocaloric effect (MCE) and refrigerant capacity or relative cooling power (RCP) of Pr 0.5 Sr 0.3 M 0.2 MnO 3 (M=Na, Li, K and Ag) materials has been investigated. A large magnetocaloric effect was inferred over a wide range of temperature around the second order paramagnetic–ferromagnetic transition. The maximum magnetic entropy changes (Δ S M ) reached 1.8, 2.2, 1.6 and 2.1 J/kg K and the relative cooling power (RCP) approached 58.9, 59.3, 69.6 and 54.6 J/kg for Na, Li, K and Ag doped materials in the magnetic change of 15 kOe, respectively. According to the results determined by the Maxwell relation, the magnetic entropy change fits well with the Landau theory of phase transition above T C for Pr 0.5 Sr 0.3 Li 0.2 MnO 3 . The large magnetic entropy change induced by low magnetic field suggested that these materials are beneficial for practical applications.

y Ba 6−3 x Eu 8+2 x Ti 18 O 54 + (1−y)Ba 6−3 x Sm 8+2 x Ti 18 O 54 ( x = 2 3 , y=0.1) (BEST) ceramic powders were synthesized by the Pechini method using ethylenediaminetetraacetic acid (EDTA) as a chelating agent. A flaxen, molecular-level, homogeneously mixed gel was prepared, and transferred into a porous resin intermediate through charring. Two-phase and well-crystallized BEST powders were prepared by calcination of the resin intermediate, without formation of any intermediate phases. Meanwhile, the crystal structure was determined by X-ray diffraction, which can be used to explain the microwave dielectric properties of BEST. The BEST ceramics prepared via EDTA precursor has good microwave dielectric characteristics: e r =52.36, Q f =2850 GHz and τ f =−24.56 ppm °C −1 .