Search Results (268)

Fe-CNT composites were synthesized via mechanical ball milling, incorporating varying amounts of carbon nanotubes (CNTs) into iron powder at concentrations of 1wt%, 2wt%, and 3wt%. The impact of different CNT contents on the phase structure, microstructure, and magnetic properties of the composites was examined. Raman spectroscopy and X-ray diffraction (XRD) analyses revealed that despite some damage, CNTs retained a predominantly one-dimensional nanostructure post-ball milling. Moreover, an increase in CNT content led to a gradual rise in grain size and lattice strain of the iron powder, attributed to the formation of solid solutions and iron–carbon compounds. Scanning electron microscopy (SEM) observations demonstrated that the majority of CNTs were integrated within the iron matrix particles, with a minority either partially embedded or entirely unembedded on the iron powder surface. With higher CNT concentrations, local CNT agglomeration emerged and intensified. Vibrating sample magnetometer (VSM) measurements indicated that Fe-CNT composites exhibited enhanced saturation magnetization (2.25%) and reduced coercivity (91.74%) compared to pure iron, underscoring the potential of CNTs in enhancing the magnetic properties of iron powder. Full article

This study investigates the structural and magnetic properties of CoFe₂O₄ nanoparticles prepared by five different synthesis methods: coprecipitation, ultrasound-assisted coprecipitation, coprecipitation coupled with mechanochemical treatment, microemulsion and microwave-assisted hydrothermal synthesis. The produced powders were additionally functionalized with starch to improve biocompatibility and colloidal stability. The starch-coating procedure itself by sonication in starch solution, as well as its result, affects the structural and magnetic properties of functionalized nanoparticles. The resulting changes of properties in the process of ligand addition depend significantly on the starting nanoparticles, or rather, on the method of their synthesis. The structural, magnetic and spectroscopic properties of the resulting materials were systematically investigated using X-ray diffraction (XRD), Raman spectroscopy, Mössbauer spectroscopy and magnetic measurements. Taken together, XRD, Raman and Mössbauer spectroscopy show that starch deposition reduces structural disorder and internal stress, resulting in nanoparticles with a more uniform size distribution. These changes, in turn, affect all magnetic properties—magnetization, coercivity and magnetic anisotropy. Magnetic responses are preserved what is desirable for future biomedical applications. This work emphasizes the importance of surface modification for tailoring the properties of magnetic nanoparticles while maintaining their desired functionality. Full article

This study investigates the structural and magnetic properties of ultra-high coercivity (Fe₈₀B₁₄Nb₆)_0.88Dy_0.12 alloys, doped with 0.5–5 at.% of selected metallic additions: magnetic (Ni, Co) and non-magnetic (Pt, Cu) elements. Material characterization involved both structural and magnetic measurements. Alloys containing dopant concentrations up to 2 at.% exhibited similar phase compositions, with the Dy₂Fe₁₄B compound being dominant. Magnetic hysteresis loops revealed a superposition of two components: magnetically soft and hard phases. A significant change in magnetic properties was observed within the 0.5 to 1 at.% dopant concentration range. Notably, the addition of 0.5 at.% Ni increased the apparent anisotropy field from 5.2 T to 7.5 T. Furthermore, 0.5 at.% Pt led to an increase in the coercive field from 4.6 T to 5.5 T. These additions influenced crystallization, resulting in the formation of a more regular microstructure without submicrometric dendrite branches, when compared to the base alloy. Full article

Ferroelectric oxides, such as Pb(Zr,Ti)O₃ (PZT), have been shown to maintain stable ferroelectricity even in ultrathin film configurations. However, achieving controllable modulation of microstructure and physical responses in these ultrathin films remains challenging, limiting their potential applications in modern nanoelectronics and optoelectronics. Here, we propose a single-pulse femtosecond (fs) laser micromachining technique for high-precision engineering of microstructure and ferroelectric/piezoelectric responses in ultrathin PZT films. The results show that various microstructures can be selectively fabricated through precise control of fs laser fluence. Specifically, nano-concave arrays are formed via low-fluence laser irradiation, which is mainly attributed to the fs laser peening effect. In contrast, nano-volcano (nano-cave) structures are generated when the laser fluence is close to or reaches the ablation threshold. Additionally, applying an fs laser pulse with fluence exceeding a critical threshold enables the formation of nano-cave structures with controlled depth and width in PZT/Pt/SiO₂ multilayers. Piezoresponse force microscopy measurements demonstrate that the laser peening process significantly enhances the piezoelectric response while exerting minimal influence on the coercive field of PZT thin films. This improvement is attributed to the enhanced electromechanical energy transfer and concentrated compressive stresses distribution in PZT thin films resulting from the laser peening effect. Our study not only offers an effective strategy for microstructure and property engineering in ferroelectric materials at the nanoscale but also provides new insights into the underlying mechanism of ultrafast laser processing in ferroelectric thin films. Full article

Introduction: Research on aggressive behaviors (ABs) in adolescent mental healthcare settings remains limited and underexplored. Such behaviors significantly affect staff, patients, and the therapeutic environment, necessitating nursing interventions for effective risk management to reduce their adverse impact on safety and quality of care. Objective: This review aimed to map the existing evidence on nursing interventions for the risk management of AB in adolescent mental health units. Methods: A search strategy was used to identify relevant studies in databases, respecting the Participant/Concept/Context (PCC) question formulation structure. This review covers studies describing nursing risk management strategies for adolescents (10 to 19 years old) with aggression problems and admitted to mental healthcare units. Results: From the 499 records initially identified, 9 articles met the inclusion criteria and were selected for review, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews (PRISMA-ScR) and its associated flow diagram. The nursing interventions identified for managing AB in adolescent healthcare settings included risk assessment tools, targeted risk management strategies, evidence-based interventions but also various forms of coercive measures. Conclusions: This review integrates current knowledge on nursing interventions for the risk management of AB in adolescent mental health units. The focus of these interventions is prevention, by early intervention strategies but also intervention programs with improved outcomes for the patient, staff and therapeutic milieu, promoting less coercive interventions and increased care quality and safety. Full article

The ordered tetragonal FeNi L1₀ phase, tetrataenite, is a promising candidate for rare earth-free permanent magnets due to its competitive magnetic properties and the low cost of the constituent elements. In this work, we have investigated the effect of molybdenum and aluminum substitution on the formation of the ordered L1₀ phase. The alloys were prepared with die casting and melt spinning techniques, further processed using cold rolling and cryomilling, and finally annealed below the estimated order–disorder temperature (T_OD). To study the influence of composition and processing of the alloys, structural characterization and microstructural analysis were performed with synchrotron radiation X-ray diffractometry (SR-PXD) and Scanning Transmission Electron Microscopy (STEM), respectively. The presence of tetrataenite in the alloys investigated in this work could not be confirmed. In situ SR-PXD and STEM indicated minimal structural changes in the temperature stability range of the materials. A full-loop hysteresis curve acquired using a vibrating sample magnetometer (VSM) indicated no signs of magnetic hardening of the alloys with the measured coercivity being below 10 Oe, and thus consistent with FeNi without ordering. Full article

The interfacial Dzyaloshinskii–Moriya interaction (DMI) plays a pivotal role in stabilising and controlling the motion of chiral spin textures, such as Néel-type bubble domains, in ultrathin magnetic films—an essential feature for next-generation spintronic devices. In this work, we investigate domain wall (DW) dynamics in magnetron-sputtered Ta(3 nm)/Pt(3 nm)/Co(1 nm)/RuO₂(1 nm) [Ru(1 nm)]/Pt(3 nm) multilayers, benchmarking their behaviour against control stacks. Vibrating sample magnetometry (VSM) was employed to determine saturation magnetisation and perpendicular magnetic anisotropy (PMA), while polar magneto-optical Kerr effect (P-MOKE) measurements provided coercivity data. Kerr microscopy visualised the expansion of bubble-shaped domains under combined perpendicular and in-plane magnetic fields, enabling the extraction of effective DMI fields. Brillouin light scattering (BLS) spectroscopy quantified the asymmetric propagation of spin waves, and micromagnetic simulations corroborated the experimental findings. The Pt/Co/RuO₂ system exhibits a Dzyaloshinskii–Moriya interaction (DMI) constant of ≈1.08 mJ/m², slightly higher than the Pt/Co/Ru system (≈1.03 mJ/m²) and much higher than the Pt/Co control (≈0.23 mJ/m²). Correspondingly, domain walls in the RuO₂-capped films show pronounced velocity asymmetry under in-plane fields, whereas the symmetric Pt/Co/Pt shows negligible asymmetry. Despite lower depinning fields in the Ru-capped sample, its domain walls move faster than those in the RuO₂-capped sample, indicating reduced pinning. Our results demonstrate that integrating RuO₂ significantly alters interfacial spin–orbit interactions. Full article

We successfully fabricated micro orthogonal fluxgate sensors using amorphous CoZrNb films. The sensor, measuring 1.5 mm × 0.5 mm, consists of three main parts: the conductor for excitation current flow, the magnetic layer sensitive to an external magnetic field, and the detection coil for measuring output voltage dependent on an external magnetic field. The magnetic layer forms a magnetically closed-circuit in the cross-section, which reduces reluctance and power consumption. Key fabrication challenges, such as poor step coverage and delamination, were effectively addressed by adjusting the sputtering angle, rotating the substrate during deposition, incorporating a Ta adhesion layer, and applying O₂ plasma surface treatment. Optimal sensor performance was achieved by vacuum annealing the CoZrNb films at 300 °C under an applied magnetic field of 500 Oe. This process effectively enhanced magnetic softness and induced magnetic anisotropy, resulting in both very low coercivity (0.1 Oe) and a stable amorphous structure. The effects of operation frequency and the conductor width on the output characteristics of the fabricated sensors were quantitatively investigated. The sensor exhibited a maximum sensitivity of 0.98 mV/Oe (=9.8 V/T). Our results demonstrate that miniaturized orthogonal fluxgate sensors suitable for multi-chip packaging can be applied to measure the Earth’s magnetic field. Full article

This study evaluates the effect of zirconium (Zr) incorporation on the structural, microstructural, and functional properties of lead-free ceramics based on the 0.95(Bi_0.5Na_0.5)TiO₃–0.05BaTiO₃ (BNT–5BT) system. Two distinct doping strategies were investigated: (i) the substitutional incorporation of Zr⁴⁺ at the Ti⁴⁺ site (BNT–5BT–xZr_sub), and (ii) the addition of ZrO₂ in excess (BNT–5BT–xZr_exc). The samples were synthesized via conventional solid-state reaction and characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM/EDS), and electrical measurements, including dielectric, ferroelectric, and piezoelectric responses. Both doping routes were found to influence phase stability and electromechanical performance. Substitutional doping notably reduced the coercive field while preserving high remanent polarization, resulting in an enhanced piezoelectric coefficient (d₃₃). These results highlight the potential of Zr-modified BNT–5BT ceramics for lead-free energy harvesting applications. Full article

It is important to accurately characterize the plane-stress state of pipe walls for evaluating the bearing capacity of the pipe and ensuring the structural safety. This paper describes a novel ultrasonic technique for evaluating anisotropic pipe-wall plane stresses using three-directional longitudinal critical refracted (LCR) wave time-of-flight (TOF) measurements. The connection between plane stress and ultrasonic TOF is confirmed by examining how the anisotropy of rolled steel plates affects the speed of ultrasonic wave propagation, which is a finding not previously documented in spiral-welded pipes. Then based on this relationship, an ultrasonic stress coefficient calibration experiment for spiral-welded pipes is designed. The results show that the principal stress obtained by the ultrasonic method is closer to the engineering stress than that obtained from the coercivity method. And, as a nondestructive testing technique, the ultrasonic method is more suitable for in-service pipelines. It also elucidates the effects of probe pressure and steel plate surface roughness on the ultrasonic TOF, obtains a threshold for probe pressure, and reveals a linear relationship between roughness and TOF. This study provides a feasible technique for nondestructive measurement of plane stress in anisotropic spiral-welded pipelines, which has potential application prospects in the health monitoring of in-service pipelines. Full article

Background/Objectives: Coercive measures remain a common practice in mental health, despite ethical concerns, potential risks, and uncertain efficacy. Mental healthcare workers’ (MHCWs) attitudes toward coercion can influence their use. However, research in Italy is limited. This study aimed to investigate Italian MHCWs’ attitudes toward coercion and their associations with sociodemographic and professional characteristics. Methods: A cross-sectional study was conducted on 356 MHCWs from a mental health department in Southern Italy. Participants completed the Staff Attitude to Coercion Scale (SACS), which assesses negative, pragmatic, and positive attitudes toward coercion. Descriptive statistics (i.e., frequencies, percentages, means) and bivariate analyses (i.e., one-way ANOVA) were used to explore the associations between variables. Results: The majority of participants were male (56.7%), nurses (50.3%), and worked in acute psychiatric settings (52%), with a mean age of 51.08 years (±10.59) and 13.74 years (±12.14) of experience in mental health. Attitudes differed significantly according to age, sex, professional role, and work setting. More negative attitudes were found among staff in residential settings and non-caring roles (p < 0.001). Pragmatic attitudes were lower among older staff (p = 0.012) and among those in residential settings and non-caring roles (p < 0.001). Positive attitudes were higher among males (p = 0.001), nursing staff (p < 0.001), and staff in acute settings (p = 0.049). Conclusions: Italian MHCWs reported different attitudes toward coercion, which was influenced by personal and professional factors. These findings highlight the need for targeted interventions and policy strategies to promote attitudinal change, particularly in settings where positive attitudes are prevalent. Full article

This study reports the synthesis and characterization of Co_xNi_1−xFe₂O₄ (x = 0, 0.2, 0.4, 0.6, 0.8, 1) nanoparticles using a co-precipitation method. In this approach, metal ions are precipitated in the presence of a stabilizing agent, which is a common and effective method for nanoparticle preparation. The microstructure and magnetic properties were studied after calcination at 600 °C and heat treatment at 1000 °C. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy confirmed the formation of a single-phase spinel structure. The average crystallite size, calculated using the (311) diffraction peak and the Scherrer equation, ranged from 13 to 19 nm. Scanning electron microscopy (SEM) showed that the nanoparticles had a spherical morphology. Thermogravimetric and differential thermal analysis (TG-DTA) revealed a three-step weight loss process. Magnetic measurements, including remanent magnetization, saturation magnetization, and coercivity, were performed using a vibrating sample magnetometer (VSM) at room temperature. The replacement of Ni²⁺ with Co²⁺ enhanced the magnetic properties, resulting in increased magnetic moment and anisotropy. These effects are attributed to changes in cation distribution, exchange interactions, surface effects, and magnetocrystalline anisotropy. Overall, Co²⁺ doping improved the magnetic behavior of nickel ferrite, indicating its potential for application in memory devices and magnetic recording media. Full article

This study intends to understand the effect of annealing behavior on the microstructure and mechanical and magnetic properties of cold-rolled extra-low-carbon steel. Deformed steel samples are annealed at temperature ranges of 200–690 °C followed by air-cooling. As part of this study, Magnetic Hysteresis loop (MHL) and Barkhausen emission (MBE) measurements are carried out for non-destructive evaluation (NDE) of the mechanical properties that are altered during annealing, viz. recovery and recrystallization. At low annealing temperature ranges 200 < T < 550 °C, the recovery causes no substantial variations in microstructure, hardness value from 191–185 HV, and tensile strength 456–452 MPa, while magnetic coercivity decreases from 293–275 A/m for cold-rolled annealed steels. The microstructural changes due to recovery and recrystallization are examined using transmission electron microscopy and orientation imaging microscopy (OIM) through electron backscattered diffraction (EBSD). Recrystallization is found after annealing at T > 550 °C, confirmed by the lowering of the microstructural KAM value from 0.81° to 0.65° and a hardness drop from 190.02 to 98 HV for cold-rolled extra-low-carbon steel. Full article

Introduction: Children living in low- and middle-income countries (LMICs) are at increased risk of emotional and behavioural challenges, often linked to caregiver stress and harsh parenting practices. Strengthening family functioning through parenting interventions is a critical strategy for improving child mental health in these settings. The Strong Families programme was developed as a light-touch family skills intervention for high-stress, low-resource environments. Methods: A multisite pilot feasibility and acceptability study was conducted in Cambodia with 40 families. Caregivers and children (aged 8–15) participated in a 3-week intervention, with one session per week. Data were collected using the Parenting and Family Adjustment Scales (PAFAS), the Strengths and Difficulties Questionnaire (SDQ), and the Child and Youth Resilience Measure (CYRM-R) at baseline, two weeks, and six weeks post-intervention. Repeated measures ANOVA and Friedman’s ANOVA were used to assess changes over time. Results: Caregivers showed statistically significant improvements across all PAFAS subscales. For example, coercive parenting scores decreased from 8.13 at baseline to 4.00 post-intervention and 2.33 at follow-up (F(2,78) = 59.76, p < 0.001). Positive encouragement improved from 2.60 to 1.00 and 0.33, respectively (F(2,78) = 27.05, p < 0.001). In terms of child outcomes, SDQ total difficulty scores declined from 20.68 to 16.55 over time (F(2,78) = 7.58, p = 0.001). Emotional problems dropped from 5.60 to 2.38 (χ²(2) = 21.17, p < 0.001), and conduct problems from 4.33 to 2.68 (F(2,78) = 11.35, p < 0.001). Prosocial behaviours increased from 5.60 to 9.45 (F(2,78) = 69.93, p < 0.001). Personal resilience scores rose from 32.70 at baseline to 47.48 at follow-up (χ²(2) = 62.42, p < 0.001), while caregiver resilience improved from 23.63 to 33.63 (χ²(2) = 61.83, p < 0.001). Improvements were particularly pronounced among families with the highest baseline challenges. Conclusions: Findings indicate that the Strong Families programme is feasible and effective in improving parenting skills, family adjustment, child mental health, and resilience in a Cambodian LMIC context. These results reinforce the programme’s potential for integration into broader national strategies to improve psychosocial outcomes for families in high-stress, low-resource environments. Full article

Recreational hunting is a highly regulated activity, in part because it can give rise to a variety of deleterious social, environmental, and economic harms. It provides an interesting area for those interested in community safety because of the way in which both formal (e.g., enforcement officers, proscribed areas and times for hunting, licensing, etc.) and informal (e.g., community awareness and education, conservation) methods of crime prevention are applied. And yet, the criminological literature on effective regulation is not only limited but diverse in terms of scope, types of behavior considered (e.g., poaching, wildlife trading, recreation, etc.), and the context that is considered (e.g., geographical, cultural, etc.). In this paper, we present how a crime prevention and compliance response can be used to understand the nature of the issue and the individual and socio-political processes that result in non-compliance with hunting regulations. We present an overview of the status of recreational hunting in an Australian jurisdiction and locate the regulatory issues that arise within the research literature that explores the various motivations that are known to drive illegal hunting. These are then considered in relation to how community-oriented and non-coercive measures might be employed to improve prevent criminal behavior at the primary, secondary, and tertiary levels. Full article