Ionic exchange effects and magnetic properties of nanocrystalline BaFe/sub 12/O/sub 19/ ferite dispersions

The objective of this study was to detect the environmental impacts generated by the municipal Mata cemetery. In order to aid in the detection and monitoring of the area were used granulometric and chemical terms through EDXRF the study of soil. Considering the results obtained it is concluded that the soil analytical results showed presence of metals in all analyzes, but with levels below the maximum permitted values of metals in Brazilian soils. The Cd was an exception, for this metal values above 0.6 mg kg-1 were found. The clay/silt ratio less than 1.5 in the investigated samples indicates a more weathered soil on the surface than at depths of 30 cm in the cemetery area. Statistical data estimate highly significant Mg, Cl, Al, Fe, K, Ti and Rh factor loads on the surface and at depths, K, Ca, Cl, Al and Mg are the most important. The main ion exchanges correlate with the correlation coefficients found within the same order. Therefore, it is possible that the simultaneous increase or decrease in the cations is the result, mainly, of ionic exchange effects in the mineral assembly of the sediments investigated.

Download Full-text

ChemInform Abstract: Exchange Effects in Three Dimensions-real Materials: Bulk Magnetic Properties of Organic Verdazyl Radical Crystals

ChemInform ◽

10.1002/chin.200001288 ◽

2010 ◽

Vol 31 (1) ◽

pp. no-no

Author(s):

Kazuo Mukai

Keyword(s):

Magnetic Properties ◽

Three Dimensions ◽

Abstract Exchange ◽

Verdazyl Radical ◽

Exchange Effects

Download Full-text

AEM analysis of crystallization in Ti-based amorphous alloys

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100075142 ◽

1983 ◽

Vol 41 ◽

pp. 270-271

Author(s):

A.R. Pelton ◽

A.F. Marshall ◽

Y.S. Lee

Keyword(s):

Magnetic Properties ◽

Amorphous Alloys ◽

Amorphous Materials ◽

Isothermal Annealing ◽

Amorphous Matrix ◽

Nucleation And Growth ◽

Current Interest ◽

Amorphous Films ◽

Electrical And Magnetic Properties

Amorphous materials are of current interest due to their desirable mechanical, electrical and magnetic properties. Furthermore, crystallizing amorphous alloys provides an avenue for discerning sequential and competitive phases thus allowing access to otherwise inaccessible crystalline structures. Previous studies have shown the benefits of using AEM to determine crystal structures and compositions of partially crystallized alloys. The present paper will discuss the AEM characterization of crystallized Cu-Ti and Ni-Ti amorphous films.Cu60Ti40: The amorphous alloy Cu60Ti40, when continuously heated, forms a simple intermediate, macrocrystalline phase which then transforms to the ordered, equilibrium Cu3Ti2 phase. However, contrary to what one would expect from kinetic considerations, isothermal annealing below the isochronal crystallization temperature results in direct nucleation and growth of Cu3Ti2 from the amorphous matrix.

Download Full-text

Microstructure in soft magnetic E3 (S1, Al) (Sendust) alloys

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100105916 ◽

1988 ◽

Vol 46 ◽

pp. 770-771

Author(s):

June D. Kim

Keyword(s):

Electron Microscopy ◽

Magnetic Properties ◽

Ternary Phase Diagram ◽

Vertical Tube ◽

Vacuum Induction Melting ◽

Induction Melting ◽

Soft Magnetic ◽

Quenching Temperature ◽

Thin Foils ◽

Vertical Tube Furnace

Iron-base alloys containing 8-11 wt.% Si, 4-8 wt.% Al, known as “Sendust” alloys, show excellent soft magnetic properties. These magnetic properties are strongly dependent on heat treatment conditions, especially on the quenching temperature following annealing. But little has been known about the microstructure and the Fe-Si-Al ternary phase diagram has not been established. In the present investigation, transmission electron microscopy (TEM) has been used to study the microstructure in a Sendust alloy as a function of temperature.An Fe-9.34 wt.% Si-5.34 wt.% Al (approximately Fe3Si0.6Al0.4) alloy was prepared by vacuum induction melting, and homogenized at 1,200°C for 5 hrs. Specimens were heat-treated in a vertical tube furnace in air, and the temperature was controlled to an accuracy of ±2°C. Thin foils for TEM observation were prepared by jet polishing using a mixture of perchloric acid 15% and acetic acid 85% at 10V and ∼13°C. Electron microscopy was performed using a Philips EM 301 microscope.

Download Full-text