Nitrogen-vacancy color centers created by proton implantation in a diamond

We present an experimental study of the longitudinal and transverse relaxation of ensembles of negatively charged nitrogen-vacancy (NV−) centers in a diamond monocrystal prepared by 1.8 MeV proton implantation. The focused proton beam was used to introduce vacancies at a 20 µµm depth layer. Applied doses were in the range of 1.5×1013 to 1.5×1017 ions/cm2. The samples were subsequently annealed in vacuum which resulted in a migration of vacancies and their association with the nitrogen present in the diamond matrix. The proton implantation technique proved versatile to control production of nitrogen-vacancy color centers in thin films

Diamond-like carbon coatings formed by ionic methods for potential use in hip joint endoprostheses : preliminary studies

Zastosowanie supertwardych powłok węglowych dla poprawy własności trybologicznych układu główka- panewka endoprotezy stawu biodrowego może znacznie wydłużyć okres pracy endoprotezy. Metody jonowe (IBSD, IBAD) [1, 2] umożliwiają formowanie złożonych powłok ochronnych o doskonałej adhezji do podłoża, a poprzez odpowiednią strukturę warstwową powłok formowanych metodami jonowymi można w istotny sposób zmniejszyć naprężenia mechaniczne układu powłoka-podłoże. Własności biochemiczne i mechaniczne powłok formowanych metodami jo nowymi silnie zależą od przebiegu słabo poznanych procesów fizycznych zachodzących w trakcie formowania powłok. Celem niniejszej pracy było określenie struktury dwuwarstwowych powłok DLC-SiC oraz DLC-TiC oraz wstępna ocena ich biozgodności w hodowlach makrofagów i fibroblastów. Wielowarstwowe powłoki formowano dwuwiązkową metodą IBAD na powierzchniach płaskich próbek wykonanych ze stali lub ze stopu Ti-AI-V. Strukturę warstwową uformowanych powłok badano metodą RBS. Odporność korozyjną uformowanych powłok oceniono jako dobrą, a stopień przeżywalności komórek hodowanych na powierzchni próbek był wysoki.Super-hard carbon coatings improve tribological properties o f the head/cup system in the hip joint prostheses, and essentially extend their working time. The ionic methods (IBSD, IBAD) [1, 2] allow obtaining complex protective coatings with perfect adhesion to the substrate. Mechanical stresses on the substrate-coating interface can be minimized by applying appropriate layer structures. Biochemical and mechanical properties of coatings formed by the ionic methods strongly depend on, not fully understood, physical processes taking place upon deposition. The objective of this work was to determine the structure of the double-layer DLC-SiC and DLC-TiC coatings and to assess their biocompatibility in the macrophag and fibroblast cultures. The multilayer coatings were formed by a dualbeam IBAD method on flat surfaces of samples of stainless steel or Ti-AI-V alloy, and their layer structure was investigated by the RBS method. The resistance to chemical corrosion turned out good and the survival rate o f cells cultured on the coated surfaces was high

Desarda technique as a valuable alternative for inguinal hernia patients refusing mesh implantation: long-term results fifteen years after a pure tissue repair in 198 patients

Aim: The aim of the study was to retrospectively analyze long-term results of surgical treatment of patients diagnosed with primary inguinal hernia up to 15 years after a Desarda pure tissue repair.Methods: The study was conducted on a group of adult patients with primary inguinal hernia who underwent elective surgery at our center during 2005-2006. Patients’ data and hernia and surgery characteristics were recorded. Incidence of postoperative complications was assessed seven days after surgery. An attempt was made to contact all patients 15 years after the procedure regarding recurrence, possible surgical re-treatment, pain, and satisfaction.Results: Desarda procedure was performed in 341 patients. Fifteen years after the surgical procedure, a follow-up was successful in 215 (63%) patients, of whom 198 (58.1%) answered all of the questions. In the early perioperative period, minor postoperative complications were found in 5.6% of patients. After 15 years of follow-up, three recurrences were found (1.5%). Recurrences occurred 2, 3, and 5 years after the surgery. All patients expressed their satisfaction with the treatment. Twenty-eight patients (14.4%) reported a rare occurrence of mild pain while performing certain activities. Three patients reported persistent chronic pain (1.5%).Conclusion: Surgical repair of primary inguinal hernia using the Desarda technique is a simple, feasible, repeatable procedure, using the patient’s own tissues, and with a low learning curve. It seems that the Desarda repair can still be a safe alternative to other non-mesh surgical techniques, especially when the patient refuses the use a synthetic mesh

Cuprous Oxide Thin Films Implanted with Chromium Ions—Optical and Physical Properties Studies

Cuprous oxide is a semiconductor with potential for use in photocatalysis, sensors, and photovoltaics. We used ion implantation to modify the properties of Cu2O oxide. Thin films of Cu2O were deposited with magnetron sputtering and implanted with low-energy Cr ions of different dosages. The X-ray diffraction method was used to determine the structure and composition of deposited and implanted films. The optical properties of the material before and after implantation were studied using spectrophotometry and spectroscopic ellipsometry. The investigation of surface topography was performed with atomic force microscopy. The implantation had little influence on the atomic lattice constant of the oxide structure, and no clear dependence of microstrain or crystalline size on the dose of implantation was found. The appearance of phase change was observed, which could have been caused by the implantation. Ellipsometry measurements showed an increase in the total thickness of the sample with an increase in the amount of implanted Cr ions, which indicates the influence of implantation on the properties of the surface and subsurface region. The refractive index n, extinction coefficient k, and absorption coefficient optical parameters show different energy dependences related to implantation dose

Influence of Cr Ion Implantation on Physical Properties of CuO Thin Films

Cupric oxide is a semiconductor with applications in sensors, solar cells, and solar thermal absorbers. To improve its properties, the oxide was doped with a metallic element. No studies were previously performed on Cr-doping using the ion implantation technique. The research goal of these studies is to investigate how Cr ion implantation impacts the properties of the oxide thin films. CuO thin films were deposited using magnetron sputtering, and then chromium ions with different energies and doses were implanted. Structural, optical, and vibrational properties of the samples were studied using X-ray diffraction, X-ray reflectivity, infra-red spectroscopy, Raman spectroscopy, and spectrophotometry. The surface morphology and topography were studied with ellipsometry, atomic force microscopy, and scanning electron microscopy. A simulation of the range of ions in the materials was performed. Ion implantation had an impact on the properties of thin films that could be used to tailor the optical properties of the cupric oxide and possibly also its electrical properties. A study considering the influence of ion implantation on electrical properties is proposed as further research on ion-implanted CuO thin films

Alternative Local Melting‐Solidification of Suspended Nanoparticles for Heterostructure Formation Enabled by Pulsed Laser Irradiation

International audiencePhase formation by pulsed laser irradiation of suspended nanoparticles has recently been introduced as a promising synthesis technique for heterostructures. The main challenge still lingers regarding the exact mechanism of particle formation due to the non‐equilibrium kinetic by‐products resulting from the localized alternative, fast, high‐temperature nature of the process. Here, the authors analyze the bond breaking/formation of copper or copper (II) interfaces with ethanol during the absorption of pulses for Cu‐CuO‐Cu 2 O formation applicable as an electrocatalyst in ethanol oxidation fuel cells. This study includes but is not limited to, a comprehensive discussion of the interaction between nano‐laser pulses and suspension for practical control of the synthesis process. The observed exponential and logarithmic changes in the content of heterostructures for the CuO‐ethanol and Cu‐ethanol samples irradiated with different fluences are interpreted as the dominant role of physical and chemical reactions, respectively, during the pulsed laser irradiation of suspensions synthesis. It is also shown that the local interface between dissociated ethanol and the molten sphere is responsible for the oxidative/reductive interactions resulting in the formation of catalytic‐augmented Cu 3+ by‐product, thanks to the reactive bond force field molecular dynamics studies confirmed by ab‐initio calculations and experimental observations