| 1. |
-
- 2019
-
Tidskriftsartikel (refereegranskat)
|
|
| 2. |
- Yuan, Ya Hua, et al.
(författare)
-
Angle-resolved photoemission spectroscopy view on the nature of Ce 4f electrons in the antiferromagnetic Kondo lattice CePd5Al2
- 2021
-
Ingår i: Physical Review B. - : American Physical Society (APS). - 2469-9969 .- 2469-9950. ; 103:12
-
Tidskriftsartikel (refereegranskat)abstract
- We report an angle-resolved photoemission spectroscopy study of the antiferromagnetic Kondo lattice CePd5Al2, focusing on the quasi-two-dimensional k-space nature of its Fermi surface and, tuning photon energy to the Ce 4d-4f on-resonance transition, the hybridization of the Ce 4f state. A strong shoulder feature on the f0 peak was detected, suggesting hybridization between conduction and f bands. On-resonance spectra revealed narrow, yet hybridized quasiparticle bands with sharp peaks and ∼ 9 meV energy dispersion near the Fermi energy EF. The observed dispersive hybridized f band can be well described by a hybridization-band picture based on the periodic Anderson model (PAM). Hence, the 4f electrons in CePd5Al2 display a dual nature, with both localized and itinerant features, but with dominantly localized character.
|
|
| 3. |
- Zaidi, A. A., et al.
(författare)
-
A Preliminary Study on Waveform Candidates for 5G Mobile Radio Communications Above 6 GHz
- 2016
-
Ingår i: IEEE Vehicular Technology Conference. - 1550-2252. ; 2016-July
-
Konferensbidrag (refereegranskat)abstract
- This paper provides an overview and preliminary comparison of several multi-carrier and single-carrier waveforms that are potential candidates for future 5G mobile radio communications above 6 GHz. The waveforms are assessed primarily based on the established and known results as well as recent findings keeping in view the design requirements that are relevant to using frequencies above 6 GHz, especially the millimeter wave frequencies. The Key Performance Indicators and degrees of freedom in the design of different waveforms and their potential applications for mm-wave communications are discussed. Certain features that are particularly interesting for mm-wave communication and require further investigations are also highlighted. Furthermore, a common framework for synthesizing different waveform candidates has been developed. Finally, a preliminary qualitative comparison of different multicarrier and single carrier waveforms has been derived.
|
|
| 4. |
- Zetterberg, P., et al.
(författare)
-
Initial multi-node and antenna transmitter and receiver architectures and schemes; Deliverable D5.1
- 2016
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This deliverable provides the initial concepts and solutions from the technical work related to multi-antenna and multi-node transceiver schemes in millimetre wave (denoted as 6-100GHz) spectrum. It also briefly presents the use cases on which the work will be based and categorises the solutions in terms of their applicability to access, backhaul and relay deployments. Another important contribution from this report is the modelling of the hardware impairments in millimetre wave transceivers and the analysis of their impact on system performance.
|
|
| 5. |
- Zhang, Chen, et al.
(författare)
-
Antiferromagnetic order in Kondo lattice CePd5Al2 possibly driven by nesting
- 2023
-
Ingår i: Physical Review B. - : American Physical Society (APS). - 2469-9950 .- 2469-9969. ; 108:3
-
Tidskriftsartikel (refereegranskat)abstract
- We investigated the electronic structure of the antiferromagnetic Kondo lattice CePd5Al2 using high-resolution angle-resolved photoemission spectroscopy. The experimentally determined band structure of the conduction electrons is predominated by the Pd 4d character. It contains multiple hole and electron Fermi pockets, in good agreement with density functional theory calculations. The Fermi surface is folded over Q0=(0,0,1), manifested by Fermi surface reconstruction and band folding. Our results suggest that Fermi surface nesting drives the formation of antiferromagnetic order in CePd5Al2.
|
|
| 6. |
- Zhang, H., et al.
(författare)
-
Ageing hardening and corrosion resistance of Fe 60 Cr 18 Cu 3 (MnCoNiMoAlTi) 19 medium-entropy alloy
- 2023
-
Ingår i: Zhongguo Youse Jinshu Xuebao/Chinese Journal of Nonferrous Metals. - 1004-0609. ; 33:8, s. 2622-2634
-
Tidskriftsartikel (refereegranskat)abstract
- Fe60Cr18Cu3(CoMnMoNiAlTi)19 medium-entropy stainless alloy (MEA) was prepared by vacuum arc furnace melting. The ageing hardening mechanism and corrosion resistance of alloy were studied. The results show that the MEA has simple BCC solid solution phase after solidification, due to the influence of medium-entropy effect. HRTEM results show that the high level of lattice distortion in the supersaturated BCC solid solution matrix leads to a high amount of nanometer-sized ordered B2 coherent precipitates after ageing treatment, and the maximum hardness of MESS after ageing reaches 621HV0.5. The resistance to corrosion in hot sulfuric acid and to pitting in the NaCl solution are both greatly improved compared with the conventional 17-4PH steel, as evidenced by more stable anodic passivation zone and significantly reduced corrosion dissolution rate in the MEA. XPS analyses results show that the multi-component passive film, which composes of high contents of anti-corrosion elements including Crhy3 +, Crox3 +, Cu+ox, Ti4ox+, Al3ox+ and Mo6ox+, is the main reason for the excellent pitting resistance and the reduced growth of pitting pit in the NaCl solution.
|
|
| 7. |
- Duan, Yu Xia, et al.
(författare)
-
Crystal electric field splitting and f -electron hybridization in heavy-fermion CePt2In7
- 2019
-
Ingår i: Physical Review B. - : AMER PHYSICAL SOC. - 2469-9969 .- 2469-9950. ; 100:8
-
Tidskriftsartikel (refereegranskat)abstract
- We use high-resolution angle-resolved photoemission spectroscopy to investigate the electronic structure of the antiferromagnetic heavy fermion compound CePt2In7, which is a member of the CeIn3-derived heavy fermion material family. Weak hybridization among 4f electron states and conduction bands was identified in CePt2In7 at low temperature much weaker than that in the other heavy fermion compounds like CeIrIn5 and CeRhIn5. The Ce 4f spectrum shows fine structures near the Fermi energy, reflecting the crystal electric field splitting of the 4f5/21 and 4f7/21 states. Also, we find that the Fermi surface has a strongly three-dimensional topology, in agreement with density-functional theory calculations. © 2019 American Physical Society.
|
|
| 8. |
- Li, G. H., et al.
(författare)
-
Surface element segregation and electrical conductivity of lithium layered transition-metal oxide cathode materials
- 2018
-
Ingår i: Applied Surface Science. - : Elsevier BV. - 0169-4332. ; 427, s. 226-232
-
Tidskriftsartikel (refereegranskat)abstract
- Surface element segregation and electric conductivity are critical in determining lithium storage ability of given cathode materials, which are poorly understood and not correlated with the structure and overall performance. Here, layered lithium transition-metal oxides, one of the state-of-the-art cathode materials for lithium ion batteries are chosen to study. A serial of LiNixCo1-2xMnxO2 samples were prepared via a solid state reaction and subsequently characterized by XRD in conjunction with structural refinement, XPS depth profiling, and AC impedance spectroscopy. Slightly different expansion rates are observed for lattice parameters (a and c/3) with varying of Ni content, which is attributed to the increase of average metalion radius and an increase of e(g) electron that enhances the columbic repulsion between transition metal and oxygen atoms. XPS depth profiling results show that surface composition is significantly deviated from bulk, in which Ni and Mn atoms tend to enrich in the surface region, while Co element is relatively deficient. Further, surface element segregation is alleviated by the increase of Ni/Mn content. Moreover, increasing the Ni/Mn content also raises the activation energy of bulk conduction.
|
|
| 9. |
- Middelburg, Luke M., et al.
(författare)
-
Impedance Spectroscopy for Enhanced Data Collection of Conductometric Soot Sensors
- 2020
-
Ingår i: IEEE International Symposium on Industrial Electronics. ; 2020-June, s. 1099-1103
-
Konferensbidrag (refereegranskat)abstract
- Impedance spectroscopy in the frequency range 100 Hz to 10 kHz has been applied to the Inter-Digitated Electrode (IDE) structure that is conventionally operated as a resistive sensor for the measurement of Particulate Matter (PM). The measurement of both the in-phase (resistive) and out-of-phase (capacitive) components of the impedance over this frequency range provides more data on PM as compared to DC resistance measurement only. Experimental validation confirms a more gradual change in capacitance with soot buildup as compared to the sudden reduction of resistance with dendrite formation. The effect of an additional vertical electric field for an increased capacitive sensitivity due to stimulated soot buildup has been experimentally investigated using the electrically conductive flow housing of the IDE structure as an additional suspended electrode.
|
|
| 10. |
- Middelburg, Luke M., et al.
(författare)
-
Maintaining transparency of a heated MEMs membrane for enabling long-term optical measurements on soot-containing exhaust gas
- 2020
-
Ingår i: Sensors. - : MDPI AG. - 1424-8220. ; 20:1
-
Tidskriftsartikel (refereegranskat)abstract
- Ensuring optical transparency over a wide spectral range of a window with a view into the tailpipe of the combustion engine, while it is exposed to the harsh environment of sootcontaining exhaust gas, is an essential pre-requisite for introducing optical techniques for long-term monitoring of automotive emissions. Therefore, a regenerable window composed of an optically transparent polysilicon-carbide membrane with a diameter ranging from 100 µm up to 2000 µm has been fabricated in microelectromechanical systems (MEMS) technology. In the first operating mode, window transparency is periodically restored by pulsed heating of the membrane using an integrated resistor for heating to temperatures that result in oxidation of deposited soot (600–700 °C). In the second mode, the membrane is kept transparent by repelling soot particles using thermophoresis. The same integrated resistor is used to yield a temperature gradient by continuous moderate-temperature heating. Realized devices have been subjected to laboratory soot exposure experiments. Membrane temperatures exceeding 500 °C have been achieved without damage to the membrane. Moreover, heating of membranes to ΔT = 40 °C above gas temperature provides sufficient thermophoretic repulsion to prevent particle deposition and maintain transparency at high soot exposure, while non-heated identical membranes on the same die and at the same exposure are heavily contaminated.
|
|
