ANTIFERROMAGNETIC TO FERROMAGNETIC TRANSITION IN CsCl-TYPE CeZn1-xCdx COMPOUNDS

Near the point of equiatomic composition, both FeRh and FeCo bulk alloys exhibit a CsCl-type (B2) chemically ordered phase that is related to specific magnetic properties, namely a metamagnetic anti-ferromagnetic/ferromagnetic transition near room temperature for FeRh and a huge magnetic moment for the FeCo soft alloy. In this paper, we present the magnetic and structural properties of nanoparticles of less than 5 nm diameter embedded in an inert carbon matrix prepared by mass-selected low-energy cluster-beam deposition technique. We obtained a CsCl-type (B2) chemically ordered phase for annealed nanoalloys. Using different experimental measurements, we show how decreasing the size affects the magnetic properties. FeRh nanoparticles keep the ferromagnetic order at low temperature due to surface relaxation affecting the cell parameter. In the case of FeCo clusters, the environment drastically affects the intrinsic properties of this system by reducing the magnetization in comparison to the bulk.

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Tensile Failure of 55-Nitinol Wire

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100113858 ◽

1975 ◽

Vol 33 ◽

pp. 46-47

Author(s):

F. I. Grace

Keyword(s):

Shape Memory ◽

Shape Memory Effect ◽

Memory Effect ◽

Stoichiometric Composition ◽

Tensile Failure ◽

Initial State ◽

Initial Shape ◽

Nitinol Wire ◽

Cscl Type ◽

Shear Transformation

An interest in NiTi alloys with near stoichiometric composition (55 NiTi) has intensified since they were found to exhibit a unique mechanical shape memory effect at the Naval Ordnance Laboratory some twelve years ago (thus refered to as NITINOL alloys). Since then, the microstructural mechanisms associated with the shape memory effect have been investigated and several interesting engineering applications have appeared.The shape memory effect implies that the alloy deformed from an initial shape will spontaneously return to that initial state upon heating. This behavior is reported to be related to a diffusionless shear transformation which takes place between similar but slightly different CsCl type structures.

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PHOTOEMISSION LINE SHAPE FOR FERROMAGNETIC TRANSITION METALS ABOVE THE CURIE TEMPERATURE

Le Journal de Physique Colloques ◽

10.1051/jphyscol:1988830 ◽

1988 ◽

Vol 49 (C8) ◽

pp. C8-87-C8-88

Author(s):

A. Ziegler

Keyword(s):

Transition Metals ◽

Curie Temperature ◽

Line Shape ◽

Ferromagnetic Transition

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Drastic improvement of Curie temperature by chemical pressure in N-type diluted magnetic semiconductor Ba(Zn,Co)$$_{2}$$As$$_{2}$$

Scientific Reports ◽

10.1038/s41598-021-86205-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Licheng Fu ◽

Yilun Gu ◽

Guoxiang Zhi ◽

Haojie Zhang ◽

Rufei Zhang ◽

...

Keyword(s):

Unit Cell Volume ◽

Diluted Magnetic Semiconductor ◽

Magnetic Semiconductor ◽

Vital Role ◽

Ferromagnetic Transition ◽

Chemical Pressure ◽

Tetragonal Crystal ◽

Tetragonal Crystal Structure ◽

Diluted Magnetic ◽

Ferromagnetic Ordering

AbstractWe report the effect of chemical pressure on the ferromagnetic ordering of the recently reported n-type diluted magnetic semiconductor Ba(Zn$$_{1-x}$$ 1 - x Co$$_{x}$$ x )$$_{2}$$ 2 As$$_{2}$$ 2 which has a maximum $$T_C$$ T C $$\sim$$ ∼ 45 K. Doping Sb into As-site and Sr into Ba-site induces negative and positive chemical pressure, respectively. While conserving the tetragonal crystal structure and n-type carriers, the unit cell volume shrink by $$\sim$$ ∼ 0.3$$\%$$ % with 15$$\%$$ % Sr doping, but drastically increase the ferromagnetic transition temperature by 18$$\%$$ % to 53 K. Our experiment unequivocally demonstrate that the parameters of Zn(Co)As$$_{4}$$ 4 tetrahedra play a vital role in the formation of ferromagnetic ordering in the Ba(Zn,Co)$$_{2}$$ 2 As$$_{2}$$ 2 DMS.

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