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An investigation on the relationship between magnetostriction and magnetization by means of the self-consistent renormalization (SCR) theory of an itinerant ferromagnet was performed for Ni2MnGa alloy. The magnetization results at the Curie temperature TC suggest that the critical index δ of H ∝ Mδ is 4.7–5.0, and this confirms Takahashi's spin fluctuation theory and the result of Nishihara et al. As a result, at TC, the relation between magnetostriction and M2 deviates from proportionality and the magnetostriction is proportional to M4. At TC, the plot of ΔL/L vs M4 crossed the point of origin. This result is in accordance with Takahashi's spin fluctuation theory. [ABSTRACT FROM AUTHOR]

X-ray diffraction experiments in pulsed magnetic fields are used for studying the giant magnetic-field-induced strain in the martensitic phase of ordered [Fe.sub.3]Pt alloy. The results have shown that the magnetic-field-induced strain associated with the rearrangement of the variants has occurred in a very fast sweeping pulsed field.

X-ray diffraction experiments in pulsed magnetic fields were performed to study the giant magnetic-field-induced strain in the martensitic phase of ordered Fe3Pt alloy. The field dependence of the arrangement of the variants (crystallographic domains) was observed directly in pulsed magnetic fields for the first time. The variants with the c axis perpendicular to the magnetic field are transformed into variants with the c axis nearly parallel to the magnetic field. Moreover, we found that the reorientation behaviors are different for different variants with the same crystallographic direction. The results demonstrate the crucial importance of microscopic investigation, such as x-ray diffraction analysis, of the martensitic transition. We also found that the magnetic-field-induced strain associated with the rearrangement of the variants occurs even in a very fast sweeping pulsed field of up to 1.9×103 T/s at 1 T. [ABSTRACT FROM AUTHOR]

Magnetic properties of Ce(sub 2)[Co(sub 1-x)Ni(sub x)](sub 7)B(sub 3) compounds with x less than equal to 0.3 is studied in the temperature region from 4.2 K to 750 K. It is concluded that the compound Ce2Co7B3 is a quasi-two-dimensional antiferromagnet and becomes Pauli paramagnetic by the Ni substitution.

Magnetic properties of Ce2(Co1-xNix)7B3 compounds with x⩽0.3 have been studied in the temperature region from 4.2 K to 750 K. It is proposed on the basis of experimental data that the compound Ce2Co7B3 has an antiferromagnetic order where the nearest two ferromagnetic layers separated by 12.9 Å couple very weakly antiferromagnetically. Observed metamagnetic transition in Ce2Co7B3 compound is caused by the spin flip. In the compounds Ce2(Co1-xNix)7B3, Ni atoms substitute preferentially the 2c-site Co atoms, and all atoms in the crystals except for the 2c-site Co atoms [=Co(0) atoms] seem to be nonmagnetic. The compound Ce2(Co1-xNix)7B3 becomes Pauli paramagnetic for x larger than about 0.24. [ABSTRACT FROM AUTHOR]

Applying mathematics in real-life situations is an important objective of mathematicseducation. Yet in Thailand, the students ' ability to connect mathematics to real-life situations is insufficient. In this study, we adapted the school sports day to provide opportunities to relate real-life situations with mathematical knowledge and skills. This study aims to describe the students' responses and the teacher's interaction during a modelling task. The designing of the modelling task, inspired by the realistic Fermi problems, involves collaboration between mathematics teachers and educators and the participation of 10th grade students. The task is set in the context of bleacher in the school sports day. Each experiment's modelling task lasted for 45 minutes and was conducted in the one-day camp with 45 students. Data were collected through observation, interview, and written task before being analysed through content analysis. The results showed that the students who had no previous mathematical modelling experience engaged in mathematical modelling processes with their friends under the guidance and support of the teacher. Most of them were able to think, make assumptions, collect data, observe, make conjectures and create mathematical models to understand and solve the modelling task.