Magnetoelastic constant of thin films determined by a four-point bending apparatus

Japanese Journal of Applied Physics ◽

10.35848/1347-4065/ac4928 ◽

2022 ◽

Author(s):

Shintaro Yoshihara ◽

hideto YANAGIHARA

Keyword(s):

Magnetic Anisotropy ◽

Plastic Material ◽

Compressive Strain ◽

Epitaxial Films ◽

Four Point Bending ◽

Lattice Strains ◽

Bending Strain ◽

Epitaxial Strain ◽

Induced Magnetic Anisotropy ◽

Good Agreement

Abstract We have developed a method to variably induce lattice strains and to quantitatively evaluate the induced magnetic anisotropy. Both tensile and compressive strains were introduced into epitaxial films of cobalt ferrite (CFO) grown on a single crystal MgO(001) substrate using a four-point bending apparatus made of a plastic material fabricated by a 3D printer. The change in magnetic anisotropy due to bending strain can be measured quantitatively by using the conventional magneto-torque meter. The strain-induced magnetic anisotropy increased with the tensile strain and decreased with the compressive strain as expected from a phenomenological magnetoelastic theory. The magnetoelastic constant obtained from the changes in bending strains shows quantitatively good agreement with that of the CFO films with a uniaxial epitaxial strain. This signifies that the magnetoelastic constant can be evaluated by measuring only one film sample with strains applied by using the bending apparatus.

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Dipole-induced magnetic anisotropy in γ-Fe2O3(001) epitaxial films

Applied Physics Letters ◽

10.1063/1.2771062 ◽

2007 ◽

Vol 91 (7) ◽

pp. 072508 ◽

Cited By ~ 6

Author(s):

H. Yanagihara ◽

J. Hagiwara ◽

M. Nakazumi ◽

Eiji Kita ◽

T. Furubayashi

Keyword(s):

Magnetic Anisotropy ◽

Epitaxial Films ◽

Induced Magnetic Anisotropy

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Growth-Induced Magnetic Anisotropy of Epitaxial Films of Mixed Garnets Containing Europium

Physical Review B ◽

10.1103/physrevb.7.1070 ◽

1973 ◽

Vol 7 (3) ◽

pp. 1070-1078 ◽

Cited By ~ 32

Author(s):

M. D. Sturge ◽

R. C. LeCraw ◽

R. D. Pierce ◽

S. J. Licht ◽

L. K. Shick

Keyword(s):

Magnetic Anisotropy ◽

Epitaxial Films ◽

Induced Magnetic Anisotropy

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Growth‐induced magnetic anisotropy in variously oriented epitaxial films of Sm‐YIGG

Journal of Applied Physics ◽

10.1063/1.1663340 ◽

1974 ◽

Vol 45 (2) ◽

pp. 925-928 ◽

Cited By ~ 15

Author(s):

F. B. Hagedorn ◽

B. S. Hewitt

Keyword(s):

Magnetic Anisotropy ◽

Epitaxial Films ◽

Induced Magnetic Anisotropy

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Epitaxial strain-induced magnetic anisotropy in Sm3Fe5O12 thin films grown by pulsed laser deposition

Journal of Magnetism and Magnetic Materials ◽

10.1016/j.jmmm.2011.06.074 ◽

2011 ◽

Vol 323 (23) ◽

pp. 3143-3146 ◽

Cited By ~ 17

Author(s):

H. Yamahara ◽

M. Mikami ◽

M. Seki ◽

H. Tabata

Keyword(s):

Thin Films ◽

Magnetic Anisotropy ◽

Pulsed Laser Deposition ◽

Pulsed Laser ◽

Laser Deposition ◽

Epitaxial Strain ◽

Induced Magnetic Anisotropy

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S116 Modeling and Measurement of Residual Macro and Lattice Strains During Four-Point Bending of Zircaloy-2

Powder Diffraction ◽

10.1154/1.2951750 ◽

2008 ◽

Vol 23 (2) ◽

pp. 182-182

Author(s):

F. Xu ◽

R. A. Holt ◽

M. R. Daymond ◽

R. B. Rogge

Keyword(s):

Four Point Bending ◽

Lattice Strains

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Constitutive Modeling of the Densification Behavior in Open-Porous Cellular Solids

Materials ◽

10.3390/ma14112731 ◽

2021 ◽

Vol 14 (11) ◽

pp. 2731

Author(s):

Ameya Rege

Keyword(s):

Constitutive Model ◽

Cell Walls ◽

Compressive Strain ◽

Pore Collapse ◽

Compressive Response ◽

Linear Elastic ◽

Nonlinear Springs ◽

Different Types ◽

Point Of Intersection ◽

Good Agreement

The macroscopic mechanical behavior of open-porous cellular materials is dictated by the geometric and material properties of their microscopic cell walls. The overall compressive response of such materials is divided into three regimes, namely, the linear elastic, plateau and densification. In this paper, a constitutive model is presented, which captures not only the linear elastic regime and the subsequent pore-collapse, but is also shown to be capable of capturing the hardening upon the densification of the network. Here, the network is considered to be made up of idealized square-shaped cells, whose cell walls undergo bending and buckling under compression. Depending on the choice of damage criterion, viz. elastic buckling or irreversible bending, the cell walls collapse. These collapsed cells are then assumed to behave as nonlinear springs, acting as a foundation to the elastic network of active open cells. To this end, the network is decomposed into an active network and a collapsed one. The compressive strain at the onset of densification is then shown to be quantified by the point of intersection of the two network stress-strain curves. A parameter sensitivity analysis is presented to demonstrate the range of different material characteristics that the model is capable of capturing. The proposed constitutive model is further validated against two different types of nanoporous materials and shows good agreement.

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Magnetic anisotropy in (Ga,Mn)As: Influence of epitaxial strain and hole concentration

Physical Review B ◽

10.1103/physrevb.79.195206 ◽

2009 ◽

Vol 79 (19) ◽

Cited By ~ 47

Author(s):

M. Glunk ◽

J. Daeubler ◽

L. Dreher ◽

S. Schwaiger ◽

W. Schoch ◽

...

Keyword(s):

Magnetic Anisotropy ◽

Hole Concentration ◽

Epitaxial Strain

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Study of Influence of Width to Thickness Ratio in Sheet Metals on Bendability under Ambient and Superimposed Hydrostatic Pressure

Applied Mechanics ◽

10.3390/applmech2030030 ◽

2021 ◽

Vol 2 (3) ◽

pp. 542-558

Author(s):

Mohammadmehdi Shahzamanian ◽

David Lloyd ◽

Amir Partovi ◽

Peidong Wu

Keyword(s):

Hydrostatic Pressure ◽

Stress Ratio ◽

Fracture Strain ◽

Stress Triaxiality ◽

Volumetric Strain ◽

Thickness Ratio ◽

Sheet Metals ◽

The Finite Element Method ◽

Bending Strain ◽

Good Agreement

The effect of the width to thickness ratio on the bendability of sheet metal is investigated using the finite element method (FEM) employing the Gurson–Tvergaard–Needleman (GTN) model. Strain path changes in the sheet with change in the width/thickness ratio. It is shown that bendability and fracture strain increase significantly by decrease in the width/thickness ratio. The stress state is almost uniaxial when the stress ratio (α) is close to zero for narrow sheets. Stress ratio is nothing but the major stress to minor stress ratio. This delays the growth and coalescence of micro-voids as the volumetric strain and stress triaxiality (pressure/effective stress) decrease. On the other hand, ductility decreases with increase in α for wider sheets. Fracture bending strain is calculated and, as expected, it increases with decrease in the width/thickness ratio. Furthermore, a brief study is performed to understand the effect of superimposed hydrostatic pressure on fracture strain for various sheet metals with different width/thickness ratios. It is found that the superimposed hydrostatic pressure increases the ductility, and that the effect of the width/thickness ratio in metals on ductility is as significant as the effect of superimposed hydrostatic pressure. Numerical results are found to be in good agreement with experimental observations.

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