Fundamental Investigation of Ferromagnetic Shape Memory Alloys: A New Perspective

2003 ◽  
Vol 785 ◽  
Author(s):  
Matthew R. Sullivan ◽  
Daniel A. Ateya ◽  
Steven Pirotta ◽  
Ashish A. Shah ◽  
G. H. Wu ◽  
...  
Keyword(s):  
Magnetic Transition ◽  
Heusler Alloys ◽  
Temperature Dependent ◽  
Ferromagnetic Shape Memory Alloys ◽  
New Perspective ◽  
Ferromagnetic Shape Memory ◽  
Domain Dynamics ◽  
First Time ◽  
Structure And Microstructure

ABSTRACTIn the present study, the evolution of micromagnetic structure and microstructure is studied in-situ both as a function of temperature and applied magnetic field, using single crystal Fe-Pd and Ni-Mn-Ga Heusler alloys. Through the development of a novel technique called ‘Magnetic Transition Spectrum’ to study temperature dependent domain dynamics, the relative sequence of micromagnetic reconfiguration with respect to the martensitic transformation has been determined for the first time. Results show that the FSMAs may be viewed as magnetic mosaics, a new perspective, which is also more amenable to modeling the physical properties of these alloys. Finally, the concept of magnetic mosaics has been used to synthesize a novel class of materials with engineered magnetic anisotropies, and is briefly discussed.

In situ study of temperature dependent magnetothermoelastic correlated behavior in ferromagnetic shape memory alloys

2004 ◽  
Vol 95 (11) ◽  
pp. 6951-6953 ◽  
Author(s):  
Matthew R. Sullivan ◽  
Daniel A. Ateya ◽  
Steven J. Pirotta ◽  
Ashish A. Shah ◽  
G. H. Wu ◽  
...  
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Temperature Dependent ◽  
Ferromagnetic Shape Memory Alloys ◽  
In Situ Study ◽  
Ferromagnetic Shape Memory

The First Principle Studies on the Ferromagnetic Shape Memory Effect of Ni2YIn(Y=Fe, Co) Heusler Alloys

2017 ◽  
Vol 727 ◽  
pp. 185-190 ◽  
Author(s):  
Zhi Ren ◽  
Jian Jiao ◽  
Yang Liu ◽  
Jing Jiang Song ◽  
Xiao Hong Zhang ◽  
...  
Keyword(s):  
Shape Memory ◽  
Magnetic Moments ◽  
Heusler Alloys ◽  
Lattice Parameter ◽  
Ferromagnetic Shape Memory Alloys ◽  
Energy Principle ◽  
Equilibrium Lattice Parameter ◽  
Ferromagnetic Shape Memory ◽  
Least Energy ◽  
Co Alloys

The atom occupied sites, structures, tetragonal transformation and magnetic properties are studied by the first principles calculations. From least energy principle, the calculated equilibrium lattice parameter is 6.03 Å and 6.00 Å for Cu2MnAl type Ni2YIn (Y=Fe, Co) alloys, respectively. The Ni2YIn (Y=Fe, Co) alloys show steady martensitic phases at c/a=1.29 and c/a=1.36 based on the EBP’s method. Ni atoms and Y (Y=Fe, Co) contribute to the total magnetic moments, and keep parallel aligned in martensitic and austenitic phases. The Ni2YIn (Y=Fe, Co) alloys are the candidates for Ferromagnetic Shape Memory Alloys.

scholarly journals Hybridization Effects in Ni-Mn Based Shape Memory Alloys: XAFS Study

2008 ◽  
Vol 52 ◽  
pp. 155-164 ◽  
Author(s):  
K.R. Priolkar ◽  
P.A. Bhobe ◽  
P.R. Sarode
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Structural Transition ◽  
Heusler Alloys ◽  
Ferromagnetic Shape Memory Alloys ◽  
Unit Cells ◽  
Ideal Tool ◽  
Multiple Unit ◽  
Ferromagnetic Shape Memory ◽  
X Ray Absorption

Martensitic and magnetic properties of ferromagnetic shape memory alloys are known to depend up on structural modulations and associated changes in the Fermi surface. These modulations although periodic and spanning over multiple unit cells, involve movement of atoms typically of the order of 0.01Å. Therefore X-ray Absorption Fine Structure (XAFS) is an ideal tool to map both, local atomic movements and changes in density of states (DOS) due to changing hybridization as the system transforms from austenitic to martensitic phase. This paper presents a compilation of our XAFS studies on the Ni-Mn based shape memory alloys. A complete description of the changes in local structure around the constituent metal ions in the following alloy compositions: Ni2+xMn1-xGa, Ni2Mn1.4Sn0.6 and Ni2Mn1.4In0.6 in the austenitic and martensitic phases have been obtained. The results give the new experimental evidence for the crucial hybridization component that influences and leads to structural transition in these Ni-Mn based Heusler alloys.

scholarly journals Formation and conversion of six temperature-dependent fluorescent ZnII-complexes containing two in situ formed N-rich heterocyclic ligands

RSC Advances ◽  
2017 ◽  
Vol 7 (12) ◽  
pp. 6994-7002 ◽  
Author(s):  
Qin Wei ◽  
Mei-Juan Wei ◽  
Yan-Jun Ou ◽  
Ji-Yuan Zhang ◽  
Xia Huang ◽  
...  
Keyword(s):  
Schiff Base ◽  
Temperature Dependent ◽  
Heterocyclic Ligands ◽  
First Time

Formation and conversion of six temperature-dependent fluorescent ZnII-complexes containing two solvothermal in situ formed N-rich heterocyclic ligands from simply N3 set Schiff base were systematically studied for the first time.

SREM observation of the interaction between the in-situ deposited Pd small particles and MgO cleavage surface

1986 ◽  
Vol 44 ◽  
pp. 382-383
Author(s):  
H.-J. Ou
Keyword(s):  
Electron Microscopy ◽  
Small Particle ◽  
Small Particles ◽  
Cleavage Surface ◽  
Metallic Particles ◽  
Microscopy Technique ◽  
Ceramic Surfaces ◽  
Reflection Electron Microscopy ◽  
New Perspective

The understanding of the interactions between the small metallic particles and ceramic surfaces has been studied by many catalyst scientists. We had developed Scanning Reflection Electron Microscopy technique to study surface structure of MgO hulk cleaved surface and the interaction with the small particle of metals. Resolutions of 10Å has shown the periodic array of surface atomic steps on MgO. The SREM observation of the interaction between the metallic particles and the surface may provide a new perspective on such processes.

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