다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

In this chapter, we will restrict our attention to the ferrites and a few other closely related materials. The great interest in ferrites stems from their unique combination of a spontaneous magnetization and a high electrical resistivity. The observed magnetization results from the difference in the magnetizations of two non-equivalent sub-lattices of the magnetic ions in the crystal structure. Materials of this type should strictly be designated as “ferrimagnetic” and in some respects are more closely related to anti-ferromagnetic substances than they are to ferromagnetics in which the magnetization results from the parallel alignment of all the magnetic moments present. We shall not adhere to this special nomenclature except to emphasize effects, which are due to the existence of the sub-lattices.

Ferromagnetic materials

Nowadays, magnetic hyperthermia constitutes a complementary approach to cancer treatment. The use of magnetic particles as heating mediators, proposed in the 1950s, provides a novel strategy for improving tumor treatment and, consequently, patient's quality of life. This review reports a broad overview about several aspects of magnetic hyperthermia addressing new perspectives and the progress on relevant features such as the ad hoc preparation of magnetic nanoparticles, physical modeling of magnetic heating, methods to determine the heat dissipation power of magnetic colloids including the development of experimental apparatus and the influence of biological matrices on the heating efficiency.

Fundamentals and advances in magnetic hyperthermia

A review is given of the formation, the crystal structure and the magnetic properties of several classes of rare earth based intermetallic compounds that lend themselves as starting materials of permanent magnets. These compounds include R2Fe14B, R2Fe14C and R2Co14B and the large class of ternary rare earth compounds having the tetragonal ThMn12 structure. Special emphasis is given to the changes in magnetic properties of R2Fe17 compounds observed after interstitial solution of C or N atoms. The magnetic properties of all these compounds are discussed in terms of current models based on intersublattice and intrasublattice exchange and the interplay between the rare earth sublattice anisotropy and 3D sublattice anisotropy. A substantial portion of the review is devoted to manufacturing routes of permanent magnets and a description of the coercivity mechanisms operative in the magnets. A comparison is made of the performance and economic costs of various types of magnets and novel applications are briefly discussed.

https://iopscience.iop.org/article/10.1088/0034-4885/54/9/001/pdf

New developments in hard magnetic materials

Nanotechnology has spurred efforts to design and produce nanoscale components for incorporation into devices. Magnetic nanoparticles are an important class of functional materials, possessing unique magnetic properties due to their reduced size (below 100 nm) with potential for use in devices with reduced dimensions. Recent advances in processing by chemical synthesis and the characterisation of magnetic nanoparticles are the focus of this review. Emphasis has been placed on the various solution chemistry techniques used to synthesise particles, including: precipitation, borohydride reduction, hydrothermal, reverse micelles, polyol, sol–gel, thermolysis, photolysis, sonolysis, multisynthesis processing and electrochemical techniques. The challenges and methods for examining the structural, morphological, and magnetic properties of these materials are described.

Chemically prepared magnetic nanoparticles

The influence of cutting technique on the magnetic properties of electrical steels

http://www.pmt.usp.br/ACADEMIC/landgraf/nossos%20artigos%20em%20pdf/02jan%20jmmm.pdf

The effects of synthesis variables on the magnetic properties of coprecipitated barium ferrite powders

In the FeNd system an additional ferromagnetic phase with Tc = 245 ± 10 °C is found. In the ternary FeNdB system, magnetic analysis shows two ferromagnetic phases with Tc = 245 and 285 °C in as-cast alloys, in addition to Fe14Nd2B. Those phases are formed through the eutectic solidification of a neodymium-rich liquid at the boron-poor side of the system, suppressing the formation of Fe14Nd2B. An annealing at 600 °C dissolves the phase with Tc = 245 °C and develops Fe14Nd2B. This results in an Hci increase from 3.9 kOe in the as-cast to 14.1 kOe in the annealed condition for an Fe-80at.%Nd-5at.%B alloy. This suggests that the dissolution of additional ferromagnetic phases in the intergranular regions of sintered FeNdB magnets might be the positive effect of the 600 °C annealing.

Additional ferromagnetic phases in the FeNdB system and the effect of a 600°C annealing

http://www.pmt.usp.br/ACADEMIC/landgraf/nossos%20artigos%20em%20pdf/06campos%20jmmm%20optimum.pdf

The optimum grain size for minimizing energy losses in iron

A new stable ferromagnetic phase is found to exist in the binary FeNd system, with composition Fe-22.8at.%Nd and Tc = 230°C. A revised phase diagram is presented. A metastable ferromagnetic phase with Tc = 245°C is found to occur in arc-melted and differential thermal analysis (DTA) samples, with different eutectic morphologies. The transformation of this phase in binary FeNd was investigated. The double peak thermal events occurring upon the solidification of the DTA samples are discussed.

Fernando José Gomes Landgraf

Papers

The influence of cutting technique on the magnetic properties of electrical steels

The effects of synthesis variables on the magnetic properties of coprecipitated barium ferrite powders

Additional ferromagnetic phases in the FeNdB system and the effect of a 600°C annealing

The optimum grain size for minimizing energy losses in iron

Solidification and solid state transformations in FeNd: A revised phase diagram