Strain-Induced Ferromagnetism in Fe-40Al Single Crystals

2000 ◽  
Vol 646 ◽  
Author(s):  
D. Wu ◽  
I. Baker
Keyword(s):  
Magnetic Susceptibility ◽  
Phase Boundary ◽  
Saturation Magnetization ◽  
Single Crystals ◽  
Crystal Orientation ◽  
Antiphase Boundary ◽  
Degree Of Deformation ◽  
Calorimetric Measurements ◽  
Cold Rolled ◽  
Anti Phase Boundary

ABSTRACTRecent research [1–3] suggests that strain-induced ferromagnetism in lightly-strained FeAl arises chiefly from anti-phase boundary tubes. Magnetic and calorimetric measurements have been performed on two different orientations of B2-structured Fe-40Al single crystals that had been cold rolled to a variety of strains. The saturation magnetization and magnetic susceptibility are related to the enthalpy associated with the annealing out of antiphase boundary tubes and, hence, to the degree of deformation and crystal orientation.

Types and configurations of domain walls in ferroelectric Bi4Ti3O12single crystals

2015 ◽  
Vol 48 (4) ◽  
pp. 1080-1088 ◽  
Author(s):  
Wanneng Ye ◽  
Chaojing Lu ◽  
Yongcheng Zhang ◽  
Yichun Zhou
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Group Theory ◽  
Phase Boundary ◽  
Single Crystals ◽  
Spontaneous Polarization ◽  
Domain Walls ◽  
Theory Analysis ◽  
Transmission Electron ◽  
Anti Phase Boundary

In the ferroelectric Bi4Ti3O12, the major componentPs(a)of spontaneous polarizationPslies along theaaxis; the componentPs(c)along thecaxis is small. The two switchable components are expected to make up various types of domain walls (DWs). According to group-theory analysis, 11 permissible types of DWs are predicted to exist theoretically, and they include five types of ferroelectric DWs, one type of anti-phase boundary (APB) and five types of APB-combined ferroelectric DWs. The five types of ferroelectric DWs arePs(a)-90° DWs,Ps(a)-180° DWs,Ps(c)-180° DWs,Ps(a)-90°/Ps(c)-180° DWs andPs-180° DWs. In Bi4Ti3O12single crystals, just the five types of ferroelectric DWs were observed using transmission electron microscopy, with no trace of APBs or APB-combined ferroelectric DWs seen. ThePs(a)-90° domains are lamellar and do not have even thickness. Both thePs(a)-90° DWs andPs(a)-90°/Ps(c)-180° DWs lie mainly on the (110) plane, but often fold to the (001) plane. ThePs(a)-180° domains are predominantly flaky. Both thePs(a)-180° DWs andPs-180° DWs lie mainly on the (001) plane. ThePs(c)-180° DWs observed are irregularly curved.

Pseudoelasticity in Fe3Al Single Crystals under Cyclic Loading

2006 ◽  
Vol 512 ◽  
pp. 25-30 ◽  
Author(s):  
Hiroyuki Y. Yasuda ◽  
Keisuke Yamaoka ◽  
Yukichi Umakoshi
Keyword(s):  
Dislocation Density ◽  
Phase Boundary ◽  
Single Crystals ◽  
Cyclic Deformation ◽  
Early Stage ◽  
Large Strain ◽  
Deformation Behaviour ◽  
Strain Recovery ◽  
Nearest Neighbour ◽  
Anti Phase Boundary

D03-ordered Fe3Al single crystals containing 23, 25 and 28at.%Al were cyclically deformed at [ 49 1 ] loading axis in tension-compression mode. Giant pseudoelasticity took place in Fe-23 and 25at.%Al single crystals at an early stage of cyclic deformation, while a slight strain recovery was observed in Fe-28at.%Al. In Fe-23 and 25at.%Al single crystals, superpartial dislocations with Burgers vector of 1/4[111] moved individually dragging the nearest neighbour anti-phase boundary (NNAPB). The NNAPB pulled back the superpartials during unloading, resulting in giant pseudoelasticity and low residual dislocation density. In contrast, a couplet of the superpartials was observed to bow out leaving two superpartials in Fe-28at.%Al. This means that the dislocation couplet dragged the next-nearest neighbour anti-phase boundary (NNNAPB). The surface tension of NNNAPB is lower than that of NNAPB resulting in a slight strain recovery in Fe-28at%Al. As cyclic deformation proceeded, residual dislocation density increased with an increase in the number of cycles even in Fe-23 and 25at.%Al. In particular, persistent slip bands (PSB) were formed in Fe-23at.%Al single crystals, though PSB is seldom observed in fatigued intermetallic compounds. To-and-fro motion of superpartials during loading and unloading was suppressed by dislocation bundles, resulting in a reduced shape recovery. However, large strain recovery occurred in Fe-25at.%Al single crystals at a strain amplitude of 1.0% even at 20cycles. It was also noted that Fe-23 and 25at.%Al demonstrated tension-compression asymmetry even at [ 49 1 ] orientation; the yield stress in compression was higher than that in tension. This implies that the core structure of <111> screw dislocation played an important role in the deformation behaviour of Fe3Al single crystals.

scholarly journals Single Crystal Growth and Physical Properties of Pyroxene CoGeO3

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 378
Author(s):  
Li Zhao ◽  
Zhiwei Hu ◽  
Hanjie Guo ◽  
Christoph Geibel ◽  
Hong-Ji Lin ◽  
...  
Keyword(s):  
High Pressure ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Crystal Growth ◽  
Physical Properties ◽  
Single Crystal ◽  
Single Crystals ◽  
Magnetic Moments ◽  
Single Crystal Growth ◽  
The Impact

We report on the synthesis and physical properties of cm-sized CoGeO3 single crystals grown in a high pressure mirror furnace at pressures of 80 bar. Direction dependent magnetic susceptibility measurements on our single crystals reveal highly anisotropic magnetic properties that we attribute to the impact of strong single ion anisotropy appearing in this system with TN∼33.5 K. Furthermore, we observe effective magnetic moments that are exceeding the spin only values of the Co ions, which reveals the presence of sizable orbital moments in CoGeO3.

Suppression of Ferromagnetism in EuxCa1-xB6

2012 ◽  
Vol 190 ◽  
pp. 97-100 ◽  
Author(s):  
V.V. Glushkov ◽  
A.V. Kuznetsov ◽  
I. Sannikov ◽  
A.V. Bogach ◽  
S.V. Demishev ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Curie Temperature ◽  
Single Crystals ◽  
Effective Magnetic Moment ◽  
Paramagnetic State ◽  
Low Field ◽  
Wide Range ◽  
Free Ion ◽  
The Eu

We report the magnetic properties of EuxCa1-xB6 single crystals (0.756x1) studied in the wide range of temperatures (1.8-300 K) and magnetic fields (up to 50 kOe). It was found that low field magnetic susceptibility χ (T) follows the Curie-Weiss law χ~(T-Θp)-1 at high temperatures for all the concentrations studied. The effective magnetic moment of the Eu2+ ion estimated from the data diminishes from the free ion value μeff7.93μB (μB - Bohr magneton) for x=1 to μeff7.3μB for x=0.756. A universal behavior of magnetic susceptibility χ~(T-Θ)-α (α=1.5) is detected close to the Curie temperature TC in the paramagnetic state at both metallic (x>xC~0.8) and dielectric (xC.

The Influence of Composition on Morphology, Structure and Magnetic Properties of Ni-Co Films on Aluminum Prepared by Electroplating Method

2013 ◽  
Vol 303-306 ◽  
pp. 2505-2509
Author(s):  
Yong Jun Hu ◽  
Dong Cao ◽  
Xi Qiang Li ◽  
Hui Ting Zheng ◽  
Xiao Ling Cheng ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Saturation Magnetization ◽  
Crystal Orientation ◽  
Nickel Content ◽  
Cobalt Content ◽  
Preferential Orientation ◽  
Content Increase ◽  
Composition Change ◽  
Alloy Films ◽  
Similar Composition

In this paper, Ni-Co alloy films with different composition were obtained by means of electroplating method. The morphology, structure and magnetic properties of Ni-Co alloy films with different Cobalt content are evaluated. The effect of the crystal orientation on the morphology of Ni-Co deposits with different compositon was discussed. The results showed that Ni–Co alloy films with Cobalt content decrease is composed of pyramidal, spindly, mixed pyramidal and spindly, and cellular particles respectively. To the deposits with similar composition, change of morphology is related to the preferential orientation. With the increase of the Nickel content, the saturation magnetization (Ms) value of the Ni–Co alloy films increases and then decreases sharply. The coercivety (Hc) value of the Ni–Co alloy films decreases with the Nickel content increase.

Magnetic properties of undoped and Co-doped n-type β–FeSi2.5 single crystals

2002 ◽  
Vol 17 (11) ◽  
pp. 2960-2965 ◽  
Author(s):  
E. Arushanov ◽  
L. Ivanenko ◽  
D. Eckert ◽  
G. Behr ◽  
U. K. Rößler ◽  
...  
Keyword(s):  
Activation Energy ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
External Field ◽  
Single Crystals ◽  
Spin Glasses ◽  
Paramagnetic Centers ◽  
Temperature Dependent ◽  
Paramagnetic Curie Temperature ◽  
Co Doped

Results of magnetization and magnetic susceptibility measurements on undoped and Co-doped FeSi2.5 single crystals are presented. The temperature dependence of the magnetic susceptibility of the Co-doped sample in the range of 5–300 K can be explained by temperature-dependent contributions due to paramagnetic centers and the carriers excited thermally in the extrinsic conductivity region. The values of the paramagnetic Curie temperature and activation energy of the donor levels were estimated. It is also shown that the magnetic susceptibility of Co-doped samples cooled in zero external field and in a field are different. This resembles the properties of spin-glasses and indicates the presence of coupling between magnetic centers.

scholarly journals Effects of Anti-phase Boundary on the Iron Loss of Grain Oriented Silicon Steel

2011 ◽  
Vol 51 (6) ◽  
pp. 987-990 ◽  
Author(s):  
Heejong Jung ◽  
Sang-Beom Kim ◽  
JinBae Kim ◽  
Jongryoul Kim
Keyword(s):  
Phase Boundary ◽  
Silicon Steel ◽  
Iron Loss ◽  
Anti Phase Boundary
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