Influence of processing parameters on nanomaterials synthesis efficiency by a carbothermal reduction process

In this work, the influence of synthesis parameters on the synthesis efficiency of tin oxide nanomaterials was studied by using the carbothermal reduction method in a sealed tube furnace. The parameters were the starting material, temperature and time of synthesis as well as the gas flux. The starting material was tin dioxide mixed with carbon black in a molar proportion of 1.5:1 and 1:1. The temperature range was from 950 to 1,125 °C with a step of 25 °C, and the synthesis times used were 15, 30, 45, 60, 75, 90, and 120 min. Using optimum values of the above parameters, the gas flux was changed to verify its influence. After completion of the syntheses, we found a grayish-black material inside the tube which was characterized by X-ray diffraction and scanning electron microscopy. The results showed that the collected material is composed of nanobelts (with width around 60 nm) and disks that grew preferentially in the SnO phase. A model based on the oxide vapor pressure was proposed to evaluate the efficiency of the process, and the results showed good agreement between experimental data and the proposed model. Based on the results obtained, the best conditions to obtain a homogeneous material with 95% efficiency is using a starting material in the molar proportion Sn:C of 1.5:1, a temperature of 1,132 °C for 75 min, and a N₂ gas flux of 80 sccm.     

Magnetization and specific heat studies of RNi4Ga (RSm,Gd and Tb)

In order to elucidate the anomalous magnetic properties in the ferromagnetically ordered state of SmNi₄Ga GdNi₄Ga and TbNi₄Ga, we have carried out a detailed study with magnetization and specific heat (SH) measurements. GdNi₄Ga shows the possibility of a filled 3d band and a helical spin arrangement below the ordering temperature. TbNi₄Ga shows a dominant crystal field effect resulting in a deviation of T_C from the de-Gennes scaling and possible Schottky anomalies in the SH. SmNi₄Ga shows a large coercivity at low temperatures. A rough estimate of the domain wall thickness in SmNi₄Ga gives a value of 8 Å.     

Superb hydroxyl radical-mediated biocidal effect induced antibacterial activity of tuned ZnO/chitosan type II heterostructure under dark

Journal of Nanoparticle Research - With the widespread use of titanium dioxide (TiO2) human exposure is inevitable, but the exposure data on TiO2 are still limited. This study adopted off-line...     

Rotational structures in the 125Cs nucleus

The collective band structures of the ¹²⁵Cs nucleus have been investigated by in-beam γ-ray spectroscopic techniques following the ¹¹⁰Pd ( ¹⁹F, 4n) reaction at 75MeV. The previously known level scheme, with rotational bands built on πg_7/2, πg_9/2 and πh_11/2 orbitals, has been extended and evolves into bands involving rotationally aligned ν(h_11/2)² and π(h_11/2)² quasiparticles. A strongly coupled band has been reassigned a high-K πh_11/2 ⊗ νg_7/2 ⊗ νh_11/2 three-quasiparticle configuration and a new side band likely to be its chiral partner has been identified. Configurations assigned to various bands are discussed in the framework of Principal/Tilted Axis Cranking (PAC/TAC) model calculations.