Search results

1

Structure and Properties of Soft-Magnetic Amorphous Bilayer Ribbons

100%

Švec P., Mat'ko I., Marcin J., Kováč J., Vlasák G., Janičkovič D., Škorvánek I., Švec P.

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issue 5

832-834

EN

Rapidly quenched bilayers consisting of Fe-Si-B and Co-Si-B layers have been prepared by planar flow casting from a single crucible with two nozzles. Temperature dependences of electrical resistivity, dilatation and magnetization have been investigated in the amorphous state and during crystallization of both layers. Preliminary studies of the structure of the layers and of the interlayer have been performed by X-ray diffraction, cross-sectional electron microscopy and microanalysis. From the results it seems evident that the process of connection of the two layers during preparation takes place by solidification with only a small extent of mutual interdiffusion of component atoms localized to a narrow well-defined interface, leading to mechanically solid connection between the two layers. The effect of combined presence of two different soft magnetic alloys on the overall magnetic properties is discussed with respect to potential applications of such materials.

2

TEM Characterization of Polysilicon and Silicide Fin Fabrication Processes of FinFETs

100%

Ratajczak J., Łaszcz A., Czerwinski A., Kątcki J., Tang X., Reckinger N., Yarekha D., Larrieu G., Dubois E.

Acta Physica Polonica A

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2009

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vol. 116

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issue S

S-89-S-91

EN

The transmission electron microscopy characterization of various silicon and silicide fin structures intended for application in FinFET devices has been performed. The results showed that transmission electron microscopy is a very useful tool for optimization of manufacturing processes of fin nanostructures in FinFETs.

3

Microstructure of Small Amount of TM Added Al-Mg-Si Alloys with Two-Step Ageing

100%

Kuroda Y., Yoshino D., Lee S., Ikeno S., Matsuda K.

Acta Physica Polonica A

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2017

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vol. 131

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issue 5

1373-1375

EN

Traditionally, Al-Mg-Si alloys are strengthened by dispersed small particles and they have medium strength with good formability. It is well known that alloying elements on Al-Mg-Si alloys (e.g. Cu) can improve mechanical properties because Cu can alter precipitation sequence. In this research, we investigated the effect of transition metals (TM) on Al-1.06at.%MgSi-TM alloys through single- and two-step ageing. Mechanical property and microstructure observation were conducted by micro Vickers hardness measurement and transmission electron microscopy.

4

TEM Observation of Cu and Ag Added Al-Mg-Si Alloy

100%

Matsumoto A., Nejigaki T., Lee S., Ikeno S., Matsuda K.

Acta Physica Polonica A

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2017

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vol. 131

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issue 5

1379-1381

EN

It is well known that Cu and Ag addition on Al-Mg₂Si alloy can enhance its mechanical properties due to solid solution hardening. Several reports are available about the effect of each alloying elements, Cu and Ag, on Al-Mg-Si alloys. In this research, Al-Mg-Si-Cu-Ag alloys have chemical compositions of (1) 0.18Cu-0.18Ag and (2) 0.35Cu-0.35Ag [at.%] fixed Cu/Ag rate of 1.0 are prepared using casting to estimate effects of Cu and Ag amount to precipitation behaviour and mechanical properties. The Vickers microhardness measurement was conducted to estimate mechanical property after ageing treatment microstructure observation was carried out using transmission electron microscopy. In peak-aged at 473 K hardness of each alloys was almost the same, but in peak-aged at 523 K, hardness of 0.35Cu-0.35Ag was higher than 0.18Cu-0.18Ag alloy.

5

Effect of the Thermal Treatment on the Microstructure and Magnetic Property of Fe_{68}Zr_{20}B_{12} Alloy Prepared by Mechanical Alloying

100%

Sun Y., Yu W., Hua Z.

Acta Physica Polonica A

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2011

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vol. 119

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issue 3

374-377

EN

Fe_{68}Zr_{20}B_{12} amorphous alloy prepared by mechanical alloying technique of 60 h of duration was annealed at different temperatures (420-720°C) during 1 h. Microstructure and magnetic property of as-milled and annealed alloy were investigated by X-ray diffraction, transmission electron microscopy, the Mössbauer spectroscopy and vibrating sample magnetometer techniques. Fe_{68}Zr_{20}B_{12} powders milled during 60 h exhibit amorphous character. After annealing at 420°C, α-Fe phase precipitates from amorphous matrix. Transmission electron microscopy analysis shows the nucleation and growth of α-Fe grains. The Mössbauer results of the annealed alloy at 670°C show that the Fe_3B phase precipitates already and there is still remaining amorphous phase. Coercivity increases with increasing annealing temperature, which is closely related to the microstructures after annealing.

6

Characterization of Precipitates in Aluminium Alloy 6013 after Cold-Rolling and Annealing

100%

Bieda M., Jarzębska A.

Acta Physica Polonica A

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2016

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vol. 130

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issue 4

988-990

EN

The aim of the present work was to observe changes in precipitations during annealing after cold-rolling. Series of the samples from cold-rolled AA6013 were prepared and compared to undeformed samples. The samples were annealed at the temperatures equal to 260, 490°C for undeformed state and at 280, 360, and 530°C for cold-rolled state. For investigation thin foils were prepared. Chemical composition and crystal structure of precipitates was analysed and described using transmission electron microscopy imaging, X-ray energy-dispersive spectroscopy and selected-area diffraction techniques. The researches indicated that low annealing temperatures caused dissolution of metastable β and Q phases. With increasing temperature there also occurred growth of Q phase. At highest annealing temperatures there were noticed precipitations of β phase again. Microstructural observation also revealed an impact of those particles on recrystallization processes.

7

XRD and TEM Heating of Large Period Ni/Al Multilayer Coatings

100%

Świątek Z., Gradys A., Maj Ł., Morgiel J., Marszałek K., Mania R., Szlezynger M.

Acta Physica Polonica A

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2016

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vol. 130

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issue 4

880-883

EN

The Ni/Al multilayer coating of λ ≈100 nm was deposited onto (001)-oriented monocrystalline silicon substrate using double target magnetron sputtering system equipped with rotating sample holder. The thicknesses of alternating layers were adjusted in the way to preserve the chemical composition ratio close to 50%Al:50%Ni (at.%). The in situ X-ray diffraction and in situ transmission electron microscopy heating experiments were carried out at relatively low heating rates (20°C/min) in order to study the phase transformation sequence. The investigations revealed that the reaction between Ni and Al multilayers starts at ≈200°C with precipitation of Al₃Ni phase, while above 300°C dominates precipitation of Ni₃Al and NiAl intermetallic phases. Both the X-ray and electron diffractions acquired at 450°C confirmed presence of the Ni₃Al and NiAl intermetallics, but the former pointed at still lasting traces of Ni(Al) solid solution.

8

3D Reconstruction of Dislocation Structures in Fe-Al_{28,40}

100%

Veselý J., Kopeček J.

Acta Physica Polonica A

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2015

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vol. 128

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issue 4

787-789

EN

Some of the experimental problems faced when attempting dislocation tomography are discussed. A method of 3D reconstruction of straight line segments with much lower experimental requirements than tomography is proposed. This method is applied to dislocation structures found in two iron aluminium alloys (28 and 40 at.% Al). Resulting information on statistical distribution of dislocation segment lengths and orientations is presented.

9

Magnetic Study of the Fe Coated by Au Nanoparticles

80%

Zeleňáková A., Kováč J., Kavečanský V., Zeleňák V.

Acta Physica Polonica A

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2008

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vol. 113

|

issue 1

533-536

EN

Nanosized iron-gold magnetic nanoparticles with an average particle size 10 nm were prepared by a reverse micelle method. The magnetic properties measurements of DC and AC magnetization confirm behaviour typical of a superparamagnetic system, such as the irreversibility of the zero-field-cooled and field-cooled curves, the frequency dependence of a blocking temperature T_B, and revealing of coercivity H_C below blocking temperature. The quantitative analysis of AC susceptibility due to value of parameter C_1 = ΔT_B/(T_B Δ log f)=0.0242 confirming the existence of inter-particle interaction in our system.

10

Some Recent Results on the 3C-SiC Structural Defects

80%

Mantzari A., Andreadou A., Marinova M., Polychroniadis E.

Acta Physica Polonica A

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2012

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vol. 121

|

issue 1

187-189

EN

This work presents some recent results on the 3C-SiC structural defects, studied by transmission electron microscopy. The samples were grown in several laboratories, using different methods. There has always been special attention to the region close to the interface between the seed and the overgrown material. This is due to the fact that this region is very important to the evolution of defects during growth. The main defects in SiC are micropipes, double position boundaries, stacking faults and dislocations. The defects that are most frequently observed in 3C-SiC and more difficult to eliminate are inclusions of other polytypes, twins and microtwins and mainly stacking faults.

11

Precession Electron Diffraction Studies of SrₓBa_{1-x}Nb₂O₆ and CaₓBa_{1-x}Nb₂O₆ Single Crystals

80%

Wspaniała-Rak J., Zubko M., Stróż D., Rak J., Dec J.

Acta Physica Polonica A

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2016

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vol. 130

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issue 4

830-832

EN

Crystal structures of two single crystals SrₓBa_{1-x}Nb₂O₆ and CaₓBa_{1-x}Nb₂O₆ have been reinvestigated using automated electron diffraction tomography method with beam precession. 3D reciprocal space has been reconstructed based on recorded tilt series. For both samples the crystal structure was refined and the tetragonal symmetry with space group P4bm was confirmed. The three dimensional reciprocal space allowed to observe and to study satellite reflections in both materials.

12

Effect of High Energy Ball Milling on the Structure and Phase Decomposition of the Multiferroic Bi₅Ti₃FeO₁₅ Ceramics

80%

Dercz J., Zubko M., Dercz G., Matuła I.

Acta Physica Polonica A

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2016

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vol. 130

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issue 4

852-855

EN

The paper presents the results of the Bi₅Ti₃FeO₁₅ multiferroic phase stability analysis during high-energy ball milling aimed at obtaining fine dispersion ceramic powder. The X-ray diffraction and transmission electron microscopy methods were used to analyse the structure and verify the degree of crystallite dispersion. Structural data analysis was carried out using the Rietveld method. To carry out the analysis of the morphology, the scanning electron microscopy was used. The results that were obtained showed that the high energy ball milling process results in the decomposition of the initial ceramics, where finally Bi₅Ti₃FeO₁₅ and Bi are obtained. An increase in the proportion of the amorphous phase and an increase in the dispersion of the grains and crystallites of the powder that occurs with an increase in the milling time were observed.

13

Increase of Hydrogen Storage Capacity of CNTs by Using Transition Metal, Metal Oxide-CNT Nanocomposites

80%

Larijani M., Safa S.

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vol. 126

|

issue 3

732-736

EN

In this paper, we examined the synergetic effect of transition metals or their oxides as decorative agent with carbon nanotubes on the hydrogen storage capacity. The TiO_2, Pd, and PdO shell nanoparticles were used as decorative agent on the surface of carbon nanotubes. The samples were investigated by X-ray diffraction, Raman spectroscopy and transmission electron microscopy. The thermal stability was investigated by thermogravimetric analysis testing. The hydrogen storage capacity was measured by a custom-made Sieverts apparatus. The Pd and TiO_2 doped carbon nanotube shows the most marked hydrogen storage capacity, 7 times higher than pristin carbon nanotubes after 30 min storage. The results show that the hydrogen storage capacity of the PdO shell- carbon nanotube composite is very low in comparison with those of two others and does not represent a significant difference with that of carbon nanotubes.

14

Characterization of Carbon Nanotubes

80%

Jeníková M., Zakuťanská K., Kováč J., Girman V., Kopčanský P., Tomašovičová N.

Acta Physica Polonica A

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2017

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vol. 131

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issue 4

952-954

EN

The aim of the presented work was to characterize single-walled carbon nanotubes as well as multi-walled carbon nanotubes by transmission electron microscopy, the Raman spectroscopy and magnetization measurements to obtain information about their size, structure, and magnetic properties. We show that having different carbon nanotubes one can easily distinguish the single-wall or multi-wall carbon nanotubes and determine their quality. The obtained results show that carbon nanotubes can be diamagnetic or ferromagnetic depending on their structural parameters.

15

Microstructure Mechanisms Governing the Creep Life of Ultrafine-Grained Cu-0.2 wt%Zr Alloy

80%

Kral P., Svoboda M., Dvorak J., Kvapilova M., Sklenicka V.

Acta Physica Polonica A

|

2012

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vol. 122

|

issue 3

457-460

EN

Equal-channel angular pressing was conducted at room temperature and extrusion was performed up to 12 passes using route where the billets were rotated by 90° in the same sense between consecutive passes. Tensile creep tests were performed at 473, 573 and 673 K at different constant applied stresses. It was observed that the original coarse grain size of unprocessed alloy was reduced to 0.3 μm after 8 equal-channel angular pressing passes and the grain growth during creep was restricted by precipitates with the mean diameter ≈ 4.0 nm. No significant effect on creep resistance was found after one equal-channel angular pressing pass at 473 and 573 K. However, the longest time to fracture was exhibited by alloy after 2 equal-channel angular pressing passes at 573 and 673 K but with further increasing number of equal-channel angular pressing passes a decrease in the time to fracture was observed. Nevertheless, the beneficial effect of equal-channel angular pressing on creep resistance was still documented after 8 passes for temperatures of 473 and 573 K. By contrast, creep tests performed at 673 K showed that the time to fracture of ultrafine-grained material is shorter as compared with that for as-received state. The 3D laser measurement of surface showed that the creep fracture process is accelerated by formation of vertical surface step relief and cavitation at the intersection of the shear bands during creep.

16

Off-Axis Electron Holography of Magnetic Nanostructures: Magnetic Behavior of Mn Rich Nanoprecipitates in (Mn,Ga)As System

80%

Barańska M., Dłużewski P., Kret S., Morawiec K., Li T., Sadowski J.

Acta Physica Polonica A

|

2017

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vol. 131

|

issue 5

1406-1408

EN

The Lorentz off-axis electron holography technique is applied to study the magnetic nature of Mn rich nanoprecipitates in (Mn,Ga)As system. The effectiveness of this technique is demonstrated in detection of the magnetic field even for small nanocrystals having an average size down to 20 nm.

17

Rare Earth Ion Implantation in GaN: Damage Formation and Recovery

80%

Gloux F., Ruterana P., Wojtowicz T., Lorenz K., Alves E.

Acta Physica Polonica A

|

2006

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vol. 110

|

issue 2

125-137

EN

Rare earth ions implanted GaN has been investigated by transmission electron microscopy versus the fluence, using Er, Eu or Tm ions at 150 keV or 300 keV and at room temperature. Point defect clusters and stacking faults are generated from low fluences (7×10^{13} at/cm^2), their density increases with the fluence up to the formation of a highly disordered layer at the surface. This highly disordered layer is observed from a threshold fluence of 3×10^{14} at/cm^2 at 150 keV and 3×10^{15} at/cm^2 at 300 keV, and appears to be composed of voids and misoriented nanocrystallites. Its thickness rapidly increases with the fluence, and then saturates. Both basal and prismatic stacking faults were observed. Basal stacking faults are I_1 in majority, but E or I_2 have also been identified. I_1 basal stacking faults propagate easily through GaN by folding from basal to prismatic planes. Channelling implantation, increasing the implantation temperature from room temperature to 500ºC, or implanting through a 10 nm thick AlN cap reduce the crystallographic damage, particularly by retarding the formation of the highly disordered layer. Implanting through the AlN cap allows the highly disordered layer formation threshold fluence to be increased by one order of magnitude, as well as the annealing at high temperature (1300ºC) which brings about a strong optical activation of the rare earths.

18

Fabrication of Si_{1-x}Ge_x Alloy on Silicon by Ge-Ion-Implantation and Short-Time-Annealing

80%

Gao K., Prucnal S., Mücklich A., Skorupa W., Zhou S.

Acta Physica Polonica A

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2013

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vol. 123

|

issue 5

858-861

EN

In our contribution we present the fabrication of Si_{1-x}Ge_x alloy by ion-implantation and millisecond flash lamp annealing. The 100 keV Ge ions at the fluence of 10×10^{16}, 5×10^{16}, and 3×10^{16} cm^{-2} were implanted into monocrystalline (100)-oriented Si wafers covered by 50 nm thermal oxide. In the consequence, the 50 nm amorphous Ge rich Si layers were obtained. The recrystallization of the implanted layers and the Si_{1-x}Ge_x alloying were accomplished by flash lamp annealing with the pulse duration of 20 ms. Flash lamp treatment at high energy densities leads to local melting of the Ge-rich silicon layer. Then the recrystallization takes place due to the millisecond range liquid phase epitaxy. Formation of the high quality monocrystalline Si_{1-x}Ge_x layer was confirmed by the μ-Raman spectroscopy, the Rutherford backscattering channeling and cross-sectional transmission electron microscopy investigation. The μ-Raman spectra reveal three phonon modes located at around 293, 404, and 432 cm^{-1} corresponding to the Ge-Ge, Si-Ge and Si-Si in the Si_{1-x}Ge_x alloy vibrational modes, respectively. Due to much higher carrier mobility in the Si_{1-x}Ge_x layers than in silicon such system can be used for the fabrication of advanced microelectronic devices.

19

Native Deep-Level Defects in MBE-Grown p-Type CdTe

80%

Olender K., Wosiński T., Mąkosa A., Dłużewski P., Kolkovsky V., Karczewski G.

Acta Physica Polonica A

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2011

|

vol. 120

|

issue 5

946-949

EN

Deep-level transient spectroscopy was used to study the defect levels in p-type CdTe layers grown by the molecular-beam epitaxy technique on lattice-mismatched GaAs substrates. In our measurements we have observed five hole traps. Two of the traps, displaying exponential capture kinetics, have been assigned to native point defects, the Cd vacancy and a complex formed of Cd vacancy and Te antisite, produced in the CdTe layers during their growth. The other two traps have been attributed to electronic states of threading dislocations on the ground of their logarithmic capture kinetics. The last trap, which was observed only when the investigated space charge region was close to the metal-semiconductor interface, has been ascribed to surface states.

20

Impact of Thin LT-GaN Cap Layers on the Structural and Compositional Quality of MOVPE Grown InGaN Quantum Wells Investigated by TEM

80%

Ivaldi F., Kret S., Szczepańska A., Czernecki R., Kryśko M., Grzanka S., Leszczyński M.

Acta Physica Polonica A

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2011

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vol. 119

|

issue 5

660-662

EN

Two samples containing InGaN quantum wells have been grown by metal-organic vapor phase epitaxy on high pressure grown monocrystalline GaN (0001). Different growth temperatures have been used to grow the wells and the barriers. In one of the samples, a low temperature GaN layer (730°C) has been grown on every quantum well before rising the temperature to standard values (900°C). The samples have been investigated by transmission electron microscopy and X-ray diffraction. Photoluminescence spectra have been measured as well. The influence of the LT-GaN has been investigated in regard to its influence on the structural and compositional quality of the sample.

Refine search results

Structure and Properties of Soft-Magnetic Amorphous Bilayer Ribbons

TEM Characterization of Polysilicon and Silicide Fin Fabrication Processes of FinFETs

Microstructure of Small Amount of TM Added Al-Mg-Si Alloys with Two-Step Ageing

TEM Observation of Cu and Ag Added Al-Mg-Si Alloy

Effect of the Thermal Treatment on the Microstructure and Magnetic Property of Fe_{68}Zr_{20}B_{12} Alloy Prepared by Mechanical Alloying

Characterization of Precipitates in Aluminium Alloy 6013 after Cold-Rolling and Annealing

XRD and TEM Heating of Large Period Ni/Al Multilayer Coatings

3D Reconstruction of Dislocation Structures in Fe-Al_{28,40}

Magnetic Study of the Fe Coated by Au Nanoparticles

Some Recent Results on the 3C-SiC Structural Defects

Precession Electron Diffraction Studies of SrₓBa_{1-x}Nb₂O₆ and CaₓBa_{1-x}Nb₂O₆ Single Crystals

Effect of High Energy Ball Milling on the Structure and Phase Decomposition of the Multiferroic Bi₅Ti₃FeO₁₅ Ceramics

Increase of Hydrogen Storage Capacity of CNTs by Using Transition Metal, Metal Oxide-CNT Nanocomposites

Characterization of Carbon Nanotubes

Microstructure Mechanisms Governing the Creep Life of Ultrafine-Grained Cu-0.2 wt%Zr Alloy

Off-Axis Electron Holography of Magnetic Nanostructures: Magnetic Behavior of Mn Rich Nanoprecipitates in (Mn,Ga)As System

Rare Earth Ion Implantation in GaN: Damage Formation and Recovery

Fabrication of Si_{1-x}Ge_x Alloy on Silicon by Ge-Ion-Implantation and Short-Time-Annealing

Native Deep-Level Defects in MBE-Grown p-Type CdTe

Impact of Thin LT-GaN Cap Layers on the Structural and Compositional Quality of MOVPE Grown InGaN Quantum Wells Investigated by TEM