Nianhua Peng

Dr Nianhua Peng


Research Fellow
+44 (0)1483 682282
15 NC 00

Academic and research departments

Advanced Technology Institute.

Biography

Research

Research interests

My publications

Publications

NH Peng, C Jeynes, R Webb, I Chakarov, DJ Kang, D Moore, M Blamire (2002)Monte Carlo simulations of energetic proton beam irradiation damage defect productions in YBCO thin films with Au masks, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS188pp. 189-195
DJ Kang, R Speaks, NH Peng, R Webb, C Jeynes, WE Booij, EJ Tarte, DF Moore, MG Blamire (2001)Nanometer scale masked ion damage barriers in YBa2Cu3O7-delta, In: IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY11(1)pp. 780-783
N Peng, C Jeynes, MJ Bailey, D Adikaari, V Stolojan, RP Webb (2009)High concentration Mn ion implantation in Si, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS267(8-9)pp. 1623-1625 ELSEVIER SCIENCE BV
DA Moseley, KA Yates, N Peng, D Mandrus, AS Sefat, WR Branford, LF Cohen (2015)Magnetotransport of proton-irradiated BaFe2As2 and BaFe1.985Co0.015As2 single crystals, In: PHYSICAL REVIEW B91(5)ARTN 05451 AMER PHYSICAL SOC
NH Peng, C Jeynes, RM Gwilliam, KJ Kirkby, RP Webb, GS Shao, DA Astill, WY Liang (2005)A potential integrated low temperature approach for superconducting MgB2 thin film growth and electronics device fabrication by ion implantation, In: IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY15(2)pp. 3265-3268
DJ Kang, NH Peng, R Webb, C Jeynes, JH Yun, SH Moon, B Oh, G Burnell, EJ Tarte, DF Moore, MG Blamire (2002)Realization and properties of MgB2 metal-masked ion damage junctions, In: APPLIED PHYSICS LETTERS81(19)pp. 3600-3602 AMER INST PHYSICS
NH Peng, DJ Kang, C Jeynes, RP Webb, DF Moore, MG Blamire, IR Chakarov (2003)High quality YBa2Cu3O7-delta Josephson junctions and junction arrays fabricated by masked proton beam irradiation damage, In: IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY13(2)pp. 889-892
C Jeynes, N Peng, NP Barradas, RM Gwilliam (2006)Quality assurance in an implantation laboratory by high accuracy RBS, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS249pp. 482-485 ELSEVIER SCIENCE BV
DP Reid, MC Stennett, B Ravel, JC Woicik, N Peng, ER Maddrell, NC Hyatt (2010)The structure of ion beam amorphised zirconolite studied by grazing angle X-ray absorption spectroscopy, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS268(11-12)pp. 1847-1852
A Ney, P Papakonstantinou, A Kumar, N-G Shang, Nianhua Peng (2011)Irradiation enhanced paramagnetism on graphene nanoflakes, In: Applied Physics Letters99(10) American Institute of Physics

We have studied the magnetization of vertically aligned graphene nanoflakes irradiated with nitrogen ions of 100 KeV energy and doses in the range 10¹¹–10¹⁷ ions/cm². The non-irradiated graphene nanoflakes show a paramagnetic contribution, which is increased progressively by ion irradiation at low doses up to 10¹⁵/cm². However, further increase on implantation dose reduces the magnetic moment which coincides with the onset of amorphization as verified by both Raman and x-ray photoelectron spectroscopic data. Overall, our results demonstrate the absence of ferromagnetism on either implanted or unimplanted samples from room temperature down to a temperature of 5 K.

C Jeynes, G Zoppi, I Forbes, MJ Bailey, N Peng (2009)Characterisation of thin film chalcogenide PV materials using MeV ion beam analysis, In: 2009 INTERNATIONAL CONFERENCE ON SUSTAINABLE POWER GENERATION AND SUPPLY, VOLS 1-4pp. 1294-1299
MG Blamire, DJ Kang, G Burnell, NH Peng, R Webb, C Jeynes, JH Yun, SH Moon, B Oh (2002)Masked ion damage and implantation for device fabrication, In: VACUUM69(1-3)pp. 11-15
F Kahlmann, WE Booij, MG Blamire, PF McBrien, EJ Tarte, NH Peng, C Jeynes, EJ Romans, CM Pegrum (2000)Transfer function and noise properties of YBa2Cu3O7-delta direct-current superconducting-quantum-interference-device magnetometers with resistively shunted inductances, In: APPLIED PHYSICS LETTERS77(4)pp. 567-569 AMER INST PHYSICS
W Guan, IM Ross, UM Bhatta, J Ghatak, N Peng, BJ Inkson, G Moebus (2013)Nanopatterning by ion implantation through nanoporous alumina masks, In: PHYSICAL CHEMISTRY CHEMICAL PHYSICS15(12)pp. 4291-4296 ROYAL SOC CHEMISTRY
MC Stennett, NC Hyatt, DP Reid, ER Maddrell, N Peng, C Jeynes, KJ Kirkby, JC Woicik, B Ravel (2009)Heavy ion implantation combined with grazing incidence X-ray absorption spectroscopy (GIXAS): A new methodology for the characterisation of radiation damage in nuclear ceramics, In: MRS Proceedings1193pp. 67-72

An understanding of the effect of cumulative radiation damage on the integrity of ceramic wasteforms for plutonium and minor actinide disposition is key to the scientific case for safe disposal. Alpha recoil due to the decay of actinide species leads to the amorphisation of the initially crystalline host matrix, with potentially deleterious consequences such as macroscopic volume swelling and reduced resistance to aqueous dissolution. For the purpose of laboratory studies the effect of radiation damage can be simulated by various accelerated methodologies. The incorporation of short-lived actinide isotopes accurately reproduces damage arising from both alpha-particle and the heavy recoil nucleus, but requires access to specialist facilities. In contrast, fast ion implantation of inactive model ceramics effectively simulates the heavy recoil nucleus, leading to amorphisation of the host crystal lattice over very short time-scales. Although the resulting materials are easily handled, quantitative analysis of the resulting damaged surface layer has proved challenging. In this investigation, we have developed an experimental methodology for characterisation of radiation damaged structures in candidate ceramics for actinide disposition. Our approach involves implantation of bulk ceramic samples with 2 MeV Kr+ ions, to simulate heavy atom recoil; combined with grazing incidence X-ray absorption spectroscopy (GI-XAS) to characterise only the damaged surface layer. Here we present experimental GI-XAS data acquired at the Ti and Zr K-edges of ion implanted zirconolite, as a function of grazing angle, demonstrating that this technique can be successfully applied to characterise only the amorphised surface layer. Comparison of our findings with data from metamict natural analogues provide evidence that heavy ion implantation reproduces the amorphous structure arising from naturally accumulated radiation damage.

W Guan, J Ghatak, Y Peng, G Möbus, N Peng, C Jeynes (2011)XTEM characterization of modulated ion implantation through self-organized anodic aluminum oxide (AAO) membranes, In: Materials Research Society Symposium Proceedings1411pp. 49-54

Penetration of a nanochannel mask by 190keV Co ions is tested for the purpose of achieving laterally modulated ion implantation into a SiO thin film on a Si substrate. A 2D-nanoporous membrane of anodic aluminum oxide (AAO) is chosen as the mask. Criteria and challenges for designing the mask are presented. Implantation experiments through a mask with pore diameter of 125 nm and inter-pore distance of 260 nm are carried out. Cross-sectional TEM (XTEM) is shown as an ideal tool to assess depth distribution and lateral distribution of implanted ions at the same time, complemented by Rutherford backscattering spectroscopy. Using energy dispersive x-ray spectroscopy linescans, a Co distribution with lateral modulation is found at 120 nm below the oxide surface. First experiments in converting the atomic distribution of Co to discrete nanoparticles by in-situ TEM annealing are presented. © 2012 Materials Research Society.

EV Yakovlev, RA Talalaev, RW Martin, C Jeynes, N Peng, CJ Deatcher, IM Watson (2006)Modeling and experimental analysis of InGaN MOVPE in the Aixtron AIX 200/4 RF-S horizontal reactor, In: Physica Status Solidi C - Current Topics in Solid State Physics, Vol 3, No 63(6)pp. 1620-1623
C Davoisne, WE Lee, MC Stennett, NC Hyatt, N Peng, C Jeynes (2010)Irradiation effects in ceramics for plutonium disposition, In: Ceramic Transactions222pp. 3-9
N Peng, C Jeynes, RM Gwilliam, KJ Kirkby, RP Webb (2007)Depth profile analysis for MgB2 thin films, formed by B implantation in Mg ribbons using energetic ion backscatterings, In: PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS460pp. 600-601

Both Rutherford backscatterings of He-4(+) beams and non-Rutherford backscatterings of He-4(+) and H+ beams have been used in this study to investigate the depth profiles of B dopant in Mg target upon B implantation and post annealing. Primitive data analysis suggests an enhanced diffusion of surface C contaminant during the B implantation process, together with enhanced surface oxidation upon implantation and thermal annealing in flowing N-2 atmosphere. Published by Elsevier B.V.

NH Peng, C Jeynes, RP Webb, IR Chakarov, MG Blamire (2001)Monte Carlo simulations of masked ion beam irradiation damage profiles in YBa2Cu3O7-delta thin films, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS178pp. 242-246
KS Shtereva, I Novotny, V Tvarozek, M Vojs, S Flickyngerova, P Sutta, A Vincze, M Milosavljević, C Jeynes, N Peng (2012)Carrier Control in Polycrystalline ZnO:Ga Thin Films via Nitrogen Implantation Electronic Materials and Processing, In: ECS Journal of Solid State Science and Technology1(5)pp. 237-240 The Electrochemical Society

The electrical characteristics of gallium-doped zinc oxide (ZnO:Ga) thin films prepared by rf diode sputtering were altered via nitrogen implantation by performing two implants at 40 keV and 80 keV with doses of 1×1015 and 1×1016 cm−2 to achieve a p-type semiconductor. An implantation of 1×1015 cm−2 N+-ions yielded a p-type with hole concentrations 1017–1018 cm−3 in some as-implanted samples. The films annealed at temperatures above 200°C in O2 and above 400°C in N2 were n-type with electron concentrations 1017–1020 cm−3. The higher nitrogen concentration (confirmed by SRIM and SIMS), in the films implanted with a 1×1016 cm−2 dose, resulted in lower electron concentrations, respectively, higher resistivity, due to compensation of donors by nitrogen acceptors. The electron concentrations ratio n(1×1015)/n(1×1016) decreases with increasing annealing temperature. Hall measurements showed that 1×1016 cm−2 N-implanted films became p-type after low temperature annealing in O2 at 200°C and in N2 at 400°C with hole concentrations of 3.2×1017 cm−3 and 1.6×1019 cm−3, respectively. Nitrogen-implanted ZnO:Ga films showed a c-axes preferred orientation of the crystallites. Annealing is shown to increase the average transmittance (>80%) of the films and to cause bandgap widening (3.19–3.3 eV).

DJ Kang, NH Peng, C Jeynes, R Webb, HN Lee, B Oh, SH Moon, G Burnell, NA Stelmashenko, EJ Tarte, DF Moore, MG Blamire (2003)Josephson effects in MgB2 metal masked ion damage junctions, In: IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY13(2)pp. 1071-1074
MC Stennett, NC Hyatt, DP Reid, ER Maddrell, N Peng, C Jeynes, KJ Kirkby, JC Woicik (2009)Characterisation of Ion Beam Irradiated Zirconolite for Pu Disposition, In: SCIENTIFIC BASIS FOR NUCLEAR WASTE MANAGEMENT XXXII1124pp. 243-248
W Guan, W Li, J Ghatak, N Peng, Y Peng, UM Bhatta, BJ Inkson, G Mobus (2012)A route for periodic nanodot fabrication in substrates using nanochanel alumina membranes as masks for ion implantation, In: Proceedings of the IEEE Conference on Nanotechnology

Progress in ion implantation of metal ions into substrates of amorphous silica or Si-nitride with respect to lateral periodic patterning is presented. We use a 2D-nanoporous membrane of anodic aluminium oxide (AAO) as mask to conduct the Co ion implantations. The criteria for successful masked implantation and main problems are presented, including testing of the masks in a focused ion beam (FIB) system. It is proposed that electron transparent thin windows are the most suitable substrate for methods development, as TEM observation can be followed without any further sample milling. Co clusters are found to exhibit the same lateral order as the pores, and first annealing tests to achieve Co nanoparticles are shown using an in-situ heating TEM holder. © 2012 IEEE.

WE Booij, CA Elwell, EJ Tarte, PF McBrien, F Kahlmann, DF Moore, MG Blamire, NH Peng, C Jeynes (1999)Electrical properties of electron and ion beam irradiated YBa2Cu3O7-delta, In: IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY9(2)pp. 2886-2889
S Hashim, DA Bradley, N Peng, AT Ramli, H Wagiran (2010)The thermoluminescence response of oxygen-doped optical fibres subjected to photon and electron irradiations, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT619(1-3)pp. 291-294
M Gilbert, C Davoisne, MC Stennett, NC Hyatt, N Peng, C Jeynes, WE Lee (2011)Krypton and helium irradiation damage in yttria-stabilised zirconia, In: Materials Research Society Symposium Proceedings1298pp. 197-202 Materials Research Society
Q Zhao, Y Liu, C Wang, S Wang, N Peng, C Jeynes (2007)Bacterial adhesion on ion-implanted stainless steel surfaces, In: APPLIED SURFACE SCIENCE253(21)pp. 8674-8681 ELSEVIER SCIENCE BV
DJ Kang, NH Peng, R Webb, C Jeynes, G Burnell, JH Yun, SH Moon, B Oh, EJ Tarte, DF Moore, M Kelly, MG Blamire (2002)Irradiation damage technology for manufacturable Josephson junctions, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS188pp. 183-188
JW Steeds, N Peng, W Sullivan (2009)Anti-site Defects are Found at Large Distances from Localised H and He Ion Implantations, In: SILICON CARBIDE AND RELATED MATERIALS 2008615-61pp. 409-412
M Gilbert, C Davoisne, M Stennett, N Hyatt, N Peng, C Jeynes, WE Lee (2011)Krypton and helium irradiation damage in neodymium-zirconolite, In: Journal of Nuclear Materials416(1-2)pp. 221-224 Elsevier
N Peng, G Shao, C Jeynes, RP Webb, RM Gwilliam, G Boudreault, DM Astill, WY Liang (2003)Ion beam synthesis of superconducting MgB2 thin films, In: APPLIED PHYSICS LETTERS82(2)pp. 236-238 AMER INST PHYSICS
N Peng, C Jeynes, RM Gwilliam, RP Webb, F Pan, X Chen (2012)On fabrication of high concentration Mn doped Si by ion implantation: problem and challenge, In: 18TH INTERNATIONAL VACUUM CONGRESS (IVC-18)32pp. 408-411
NH Peng, I Chakarov, C Jeynes, R Webb, W Booij, M Blamire, M Kelly (2000)2D Monte Carlo simulation of proton implantation of superconducting YBa2Cu3O7-delta thin films through high aspect ratio Nb masks, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS164pp. 979-985
C Davoisne, MC Stennett, NC Hyatt, Nianhua Peng, Christopher Jeynes, WE Lee (2011)Krypton irradiation damage in Nd-doped zirconolite and perovskite, In: Journal of Nuclear Materials415(1)pp. 67-73 Elsevier

Understanding the effect of radiation damage and noble gas accommodation in potential ceramic hosts for plutonium disposition is necessary to evaluate their long-term behaviour during geological disposal. Polycrystalline samples of Nd-doped zirconolite and Nd-doped perovskite were irradiated ex situ with 2 MeV Kr+ at a dose of 5 1015 ions cm2 to simulate recoil of Pu nuclei during alpha decay. The feasibility of thin section preparation of both pristine and irradiated samples by Focused Ion Beam sectioning was demonstrated. After irradiation, the Nd-doped zirconolite revealed a well defined amorphous region separated from the pristine material by a thin (40–60 nm) damaged interface. The zirconolite lattice was lost in the damaged interface, but the fluorite sublattice was retained. The Nd-doped perovskite contained a defined irradiated layer composed of an amorphous region surrounded by damaged but still crystalline layers. The structural evolution of the damaged regions is consistent with a change from orthorhombic to cubic symmetry. In addition in Nd-doped perovskite, the amorphisation dose depended on crystallographic orientation and possibly sample configuration (thin section or bulk). Electron Energy Loss Spectroscopy revealed Ti remained in the 4+ oxidation state but there was a change in Ti coordination in both Nd-doped perovskite and Nd-doped zirconolite associated with the crystalline to amorphous transition.