Research Articles (Physics)
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Item SALT spectroscopic follow-up of the G4-Jy SampleWhite, Sarah V.; Thorat, Kshitij; Mogotsi, Moses; Skelton, Rosalind; Randriamampandry, Solohery; Romero-Colmenero, Encarni; Sejake, Precious K.; Massaro, Francesco; García-Pérez, Abigail; Jiménez-Gallardo, Ana; Peña-Herazo, Harold; Taylor, Edward N. (Cambridge University Press, 2025-06)The GLEAM 4-Jy (G4Jy) Sample is a thorough compilation of the 'brightest' radio sources in the southern sky (Declination < 30 deg), as measured at 151 MHz (S > 4.0 Jy) with the Murchison Widefield Array (MWA), through the GaLactic and Extragalactic All-sky MWA (GLEAM) Survey. In addition to flux-density measurements, the G4Jy catalogue provides host-galaxy identifications (through careful visual-inspection) and four sets of spectral indices. Despite their brightness in the radio, many of these sources are poorly-studied, with the vast majority lacking a spectroscopic redshift in published work. This is crucial for studying the intrinsic properties of the sources, and so we conduct a multi-semester observing campaign on the Southern African Large Telescope (SALT), with optical spectroscopy enabling us to provide new redshifts to the astronomical community. Initial results show that not all of the host galaxies exhibit emission-line spectra in the optical (~4500-7500 Ang), which illustrates the importance of radio-frequency selection (rather than optical selection) for creating an unbiased sample of active galactic nuclei. By combining SALT redshifts with those from the 6-degree Field Galaxy Survey (6dFGS) and the Sloan Digital Sky Survey (SDSS), we calculate radio luminosities and linear sizes for 299 G4Jy sources (which includes one newly-discovered giant radio-galaxy, G4Jy 604). Furthermore, with the highest redshift acquired (so far) being z ~ 2.2 from SDSS, we look forward to evolution studies of this complete sample, as well as breaking degeneracies in radio properties with respect to, for example, the galaxy environment.Item Facile room-temperature solution-phase synthesis of a ZIF-67 : Ni hybrid-MOF battery type material for supercapacitor applicationsDiop, Ndeye Fatou; Otun, Kabir Opeyemi; Thior, Souleymane; Maphiri, Vusani Muswa; Kitenge, Vianney Ngoyi; Sarr, Samba; Sylla, Ndeye Fatou; Wenqiang, Xiang; Chaker, Mohamed; Ngom, Balla Diop; Manyala, Ncholu I. (Royal Society of Chemistry, 2025-09)Metal–organic frameworks (MOFs) have gained significant attention as potential supercapacitor electrodes due to their high surface area, tunability, and well-defined porosity. However, their application is often limited by low capacity, poor electrical conductivity, and weak substrate adhesion, as observed in zeolitic imidazolate framework-67 (ZIF-67). To address these limitations, this study investigates the effect of nickel incorporation into ZIF-67, aiming to enhance its electrochemical performance. A series of hybrid-MOFs, denoted as ZIF-67 : Ni (1 : X), were synthesized via a simple solution-phase method at room temperature by varying the nickel content. Nickel was introduced to facilitate faster redox reactions and improve ion transport, thereby enhancing charge storage capability. The optimized ZIF-67 : Ni (1 : 2) electrode exhibited a high specific capacity of 161.2 mA h g−1 at 1 A g−1, with a capacity retention of 74.6% after 5000 charge–discharge cycles, outperforming pristine ZIF-67 and other nickel-mixture variants. The improved electrochemical performance is attributed to the enhanced porous structure, which increased active site accessibility and reduced charge transfer resistance. Furthermore, an asymmetric supercapacitor device assembled using ZIF-67 : Ni (1 : 2) as the positive electrode and activated carbon (AC) as the negative electrode (ZIF-67 : Ni (1 : 2)//AC) demonstrated a cell capacity of 44.6 mA h g−1, a specific energy of 36.97 W h kg−1, and a specific power of 416.3 W kg−1 at 0.5 A g−1. Notably, the device exhibited excellent cycling stability, retaining 99.8% of its capacity after 10 000 cycles at 10 A g−1. These findings highlight the potential of multi-metallic interactions in enhancing the electrochemical performance of ZIF-67-based MOFs, offering valuable insights for the development of high-performance supercapacitor electrodesItem Enhancing organic solar cell performance via Cu nanorods-doped PEDOT:PSS : a pathway to efficient charge transport and plasmonic enhancementSeimela, Thapelo Ephraim; Hamed, Mohamed S.G.; Diale, M. (Mmantsae Moche) (Royal Society of Chemistry, 2025-07)Copper nanorods (CuNRs) were synthesized through hydrothermal reduction and used as dopants in the buffer transport layer of polymer solar cells. The CuNRs were incorporated into the hole transport layer of thin-film organic solar cells (TFPSCs) to facilitate charge transport processes. The investigation employs a conventional device architecture for fabricating the solar cells. The results show that the power conversion efficiency (PCE) increased from 3.93% (pristine device) to 5.60% (device with 2% CuNRs), representing an improvement of over 42% compared to the pristine device. The enhanced performance is primarily attributed to the improved localized surface plasmon resonance induced by the CuNRs into the PEDOT:PSS, which enhances charge transport at the interface and reduces charge carrier recombination. In the optimized device with CuNRs doped in the PEDOT:PSS hole transport layer, the highest recorded PCE was 5.60%, demonstrating this approach's effectiveness of the CuNRs in the HTL. The effective use of CuNRs to enhance charge transport and plasmonic effects in thin-film organic solar cells.Item Temperature-dependent phase evolution of the Gd3+ doped strontium compounds : structural and optical propertiesDlamini, C.; Mhlongo, M.R.; Maphiri, Vusani M.; Malevu, T.D.; Koao, Lehlohonolo Fortune; Motaung, Tshwafo Elias; Hlatshwayo, Thulani Thokozani; Motloung, Setumo Victor (Elsevier, 2025-12)Please read abstract in the article.Item Strain-mediated boron adsorption and diffusion at graphene/Ag(111) interfaces : a DFT study of substrate effectsKochaev, Aleksey; Mapasha, Refilwe Edwin; Maslov, Mikhail; Katin, Konstantin (American Chemical Society, 2025)Atomistic modeling of heterogeneous material systems faces a fundamental challenge in determining which structural component within a unit cell should undergo applied (imposed) deformation. Using graphene on Ag(111) substrate as a model system, we show that while interlayer binding energies remain nearly identical (<1% variation) regardless of whether deformation is applied to graphene, substrate, or both, the adsorption energy of boron adatoms exhibits an 11% dependence on unit cell configuration. Most remarkably, boron adatom diffusion coefficients exhibit extreme computational sensitivity, showing order-of-magnitude variations at 300 K across different modeling approaches. The substrate’s intrinsic effects are revealed through comparison with both pristine and deformed free-standing graphene.Item Unleashing the potential in energy storage : the impact of redox electrolytes on specific energy in an asymmetric supercapacitorMutua, Hellen Ngunya; Tarimo, Delvina Japhet; Maphiri, Vusani; Rutavi, Gift; Mwabora, Julius; Musembi, Robinson; Manyala, Ncholu I. (Elsevier, 2026-01)Adding redox-active species to potassium hydroxide (KOH) enhances the electrolyte's charge storage capacity through redox reactions, thereby improving stability and broadening the potential window. This study introduces a novel mediated electrolyte with good solubility, stability, and improved reversibility. Different concentrations (0.05 M, 0.07 M, and 0.09 M) of potassium ferrocyanide (KF) were separately mixed with 3 M KOH (K3) in equal volume ratios to form the redox-active electrolytes. 0.07 M (KF70) showed superior electrochemical properties when mixed with K3. The electrolyte's ionic conductivity increased from 25.3 mS/cm for KF70 to 257.3 mS/cm after adding KF70 into K3 (K3_KF70), with a corresponding viscosity of 1.32 mPas. Hexagonal boron nitride/activated carbon composite (hBN/AC-1:0.05) electrode's specific capacity rose from 676.5C/g in K3 to 847.0C/g in K3_KF70, measured in a half-cell configuration within a potential range of 0.0–0.4 V vs. Ag/AgCl. The constructed device revealed a specific energy of 58 Wh/kg in K3_KF70, which is higher compared to 24.1 Wh/kg in K3. Additionally, the device presented a specific power of 993.7 W/kg. These results present a potential pathway for significantly enhancing specific energy in supercapacitors by facilitating additional charge storage through Faradaic redox reactions occurring within the electrolyte. HIGHLIGHTS • Chronoamperometric electrodeposition was used for composite synthesis. • A redox additive improved the aqueous electrolyte performance. • Redox electrolyte influences charge storage in composite materials. • Improved specific energy is achieved in the redox electrolyte supercapacitors.Item Investigating the catalytic performance of Nb2S2C TMCC monolayer for lithium-sulfur batteriesMartins, Nicolas F.; Mapasha, Refilwe Edwin; Fwalo, Chewe; Elaggoune, Warda; Laranjeira, Jose. A.S.; Sambrano, Julio R. (Elsevier, 2026-01)Please read abstract in the article.Item First-principles study on the role of Ti, V, and Sc catalysts in enhancing the catalytic effects of boron oxide monolayer for efficient Lithium-selenium batteriesMapasha, Refilwe Edwin; Fwalo, Chewe; Igumbor, Emmanuel; Hasan, S.F.; Hussain, T. (Elsevier, 2025-09)Please read abstract in the article.Item Surface and structural changes in SiC pre-implanted with helium, silver, and strontium after annealing, and their effect on silver and strontium migrationNtshobeni, Gcobani; Abdalla, Zaki Adam Yousif; Abdelbagi, H.A.A.; Sohatsky, A.; Nguyen, T.; Njoroge, Eric Gitau; Skuratov, V.A.; Mlambo, M.; Hlatshwayo, Thulani Thokozani (Elsevier, 2025-10)Please read abstract in the article.Item Enhancing potential window with ionic liquid/water in salt mixture in co-doped activated carbon electrodes for high-energy supercapacitorsThior, Souleymane; Kitenge, Vianney Ngoyi; Diop, Ndeye Fatou; Otun, Kabir Opeyemi; Maphiri, Vusani Muswa; Adam, Rashed Ali Mohamed; Ngom, Balla Diop; Manyala, Ncholu I. (Elsevier, 2026-01-01)Please read abstract in the article.Item Investigating the Hi distribution and kinematics of ESO444-G084 and [KKS2000]23 : new insights from the MHONGOOSE surveyNamumba, B.; Ianjamasimanana, R.; Koribalski, B.S.; Bosma, A.; Athanassoula, E.; Carignan, C.; Józsa, G.I.G.; Kamphuis, P.; Deane, Roger; Sikhosana, S.P.; Verdes-Montenegro, L.; Sorgho, A.; Ndaliso, X.; Amram, P.; Brinks, E.; Chemin, L.; Combes, F.; De Blok, W.J.G.; Deg, N.; English, J.; Healy, J.; Kurapati, S.; Marasco, A.; Mc Gaugh, S.S.; Oman, K.A.; Spekkens, K.; Veronese, S.; Wong, O.I. (EDP Sciences, 2025-07)We present the HI distribution, kinematics, mass modeling, and disk stability of the dwarf irregular galaxies ESO444-G084 and [KKS2000]23 using high-resolution, high-sensitivity MHONGOOSE survey data from MeerKAT. ESO444-G084 shows centrally concentrated HI emission, while [KKS2000]23 exhibits irregular high-density clumps. Total HI fluxes measured down to 10^19 and 10^18 cm^-2 are nearly identical, indicating that the increased HI diameter at lower column densities results mainly from the larger beam, with no significant extra emission detected. We derive total HI masses of (1.1 +/- 0.1) x 10^8 and (6.1 +/- 0.3) x 10^8 solar masses for ESO444-G084 and [KKS2000]23, respectively. Using PyFAT and TiRiFiC, we extract 3D rotation curves that reveal disk-like kinematics in both galaxies. ESO444-G084 shows a warp beyond ~1.8 kpc and a fast-rising curve consistent with a centrally concentrated dark matter distribution, while [KKS2000]23's more gradual rise suggests a more extended halo. Mass modeling with an isothermal halo and stellar mass-to-light ratios of 0.20 for ESO444-G084 and 0.18 for [KKS2000]23 yields consistent results. We analyze disk stability using spatially resolved Toomre Q and gas-to-critical surface density ratios, linking these with H-alpha and FUV-based star formation. ESO444-G084 supports localized star formation despite global stability, while [KKS2000]23 appears gravitationally unstable yet lacks H-alpha, suggesting that turbulence, gas depletion, or past feedback suppresses star formation. No inflows or outflows are detected, indicating internal processes regulate star formation. This study highlights the interplay between HI morphology, kinematics, dark matter distribution, and disk stability, showing how internal processes shape dwarf galaxy evolution.Item Probing the formation of megaparsec-scale giant radio galaxies. I. Dynamical insights from MHD simulationsGiri, Gourab; Bagchi, Joydeep; Thorat, Kshitij; Deane, Roger; Delhaize, Jacinta; Saikia, D.J. (EDP Sciences, 2025-01)CONTEXT : Giant radio galaxies (GRGs), a minority among the extended-jetted population, form in a wide range of jet and environmental configurations, complicating the identification of the growth factors that facilitate their attainment of megaparsec scales. AIMS : This study aims to numerically investigate the hypothesized formation mechanisms of GRGs extending ≳ Mpc to assess their general applicability. METHODS : We employ triaxial ambient medium settings to generate varying levels of jet frustration and simulate jets with low and high power from different locations in the environment, formulating five representations. RESULTS : The emergence of distinct giant phases in all five simulated scenarios suggests that GRGs may be more common than previously believed, a prediction to be verified with contemporary radio telescopes. We find that different combinations of jet morphology, power, and the evolutionary age of the formed structure hold the potential to elucidate different formation scenarios. The simulated lobes are over-pressured, prompting further investigation into pressure profiles when jet activity ceases, potentially distinguishing between relic and active GRGs. We observed a potential phase transition in giant radio galaxies, marked by differences in lobe expansion speed and pressure variations compared to their smaller evolutionary phases. This suggests the need for further investigation across a broader parameter space to determine if GRGs fundamentally differ from smaller RGs. Axial ratio analysis reveals self-similar expansion in rapidly propagating jets, with notable deviations when the jet forms wider lobes. Overall, this study emphasizes that multiple growth factors at work can better elucidate the current-day population of GRGs, including scenarios e.g., growth of GRGs in dense environments, GRGs of several megaparsecs, GRG development in low-powered jets, and the formation of X-shaped GRGs.Item MeerKAT 1.3 GHz observations of the wide-angle tail radio galaxy J1712-2435Cotton, W.D.; Giri, Gourab; Agnihotri, P.J.; Saikia, D.J.; Thorat, Kshitij; Camilo, F. (IOP Publishing, 2025-08)We present full polarization MeerKAT images of the wide-angle tail, giant radio galaxy J17122435 at 1.3 GHz with 7.\asec5 resolution and an RMS sensitivity of 8 Jy beam. Due to the angular proximity to the Galactic Center (l=359.6, b=+8.5) the immediate environment is not well understood but there are massive clusters nearby. Emission can be traced over an extent of 34.\amin6 which at the redshift of 0.024330 corresponds to a projected length of 1.02 Mpc. The inner jets are quite straight but then bend and completely decollimate into extended plumes nearly orthogonal to the initial jet directions at a projected distance of approximately 100 kpc. The nearly unity brightness ratio of the inner jets suggest that they are orientated within a few degrees of the plane of the sky. The 1400 MHz power is 3.9 W Hz, somewhat below the FRI/FRII divide. The total power emitted is estimated to be 5.6 erg sec over the range 10 MHz to 100 GHz. The source dynamics are modeled with magneto-hydrodynamics simulations; the result is a rough reproduction of the source's radio morphology / appearance. This study further highlights the merit of alternative scenarios, calling for future observational and numerical efforts.Item Low-velocity precessing jets can explain observed morphologies in the Twin Radio Galaxy TRGJ104454+354055Mondal, Santanu; Giri, Gourab; Joshi, Ravi; Wiita, Paul J.; Krishna, Gopal; Ho, Luis C. (IOP Publishing, 2025-07)Our understanding of large-scale radio jets in merger systems has been drastically improved in the era of VLA, VLBA/EVN, uGMRT, and MeerKAT. Twin Radio Galaxies (TRGs) are the rare interacting galaxy pairs where both supermassive black holes host kiloparsec-scale bipolar radio jets. Only recently was a third TRG discovered and it shows significantly different jet morphologies than the previous two. Due to both the extreme paucity and complexity of such systems, the launching of their jets as well as their mutual interaction during the propagation through the ambient medium are not well understood. We have performed 3D hydrodynamic simulations to study the bipolar jets in the third TRG, J104454+354055. Our study indicates that the precession of mutually tilted bipolar jets originating from the two galactic nuclei separated by tens of kiloparsecs and propagating at low velocities can explain the observed morphologies. The simulated jet precession timescales are short compared to the overall dynamical timescale of the jets and could originate from Lense-Thirring effects in the accretion disks. This approach to understanding the TRG jet dynamics could also be applied to other TRG systems with similar helical morphologies that may be discovered in the upcoming era of the SKA and its pathfinder surveys.Item Detection of millimetre-wave coronal emission in a quasar at cosmological distance using microlensingRybak, M.; Sluse, D.; Gupta, K.K.; Millon, M.; Beha, E.; Courbin, F.; McKean, J.P.; Stacey, H.R. (EDP Sciences, 2025-09)Determining the nature of emission processes at the heart of quasars is critical for understanding environments of supermassive black holes. One of the key open questions is the origin of centimetre- to millimetre-wave emission from radio-quiet quasars. The proposed mechanisms range from central star formation to dusty torus, low-power jets, or emission from the accretion-disc corona. Distinguishing between these scenarios requires probing spatial scales of ≤0.01 pc, beyond the reach of any current millimetre-wave telescope. Fortunately, in gravitationally lensed quasars, compact millimetre-wave emission might be microlensed by stars in the foreground galaxy, providing strong constraints on the source size. We report a striking change in rest-frame 1.3 mm flux ratios in RXJ1131−1231, a quadruply lensed quasar at z = 0.658 observed by the Atacama Large Millimeter/submillimeter Array (ALMA) in 2015 and 2020. Over this period, the flux ratios between the three quasar images, A, B, and C, changed by a factor of 1.6 (A/B) and 3.0 (A/C). The observed flux-ratio variability is consistent with the microlensing of a compact source with a half-light radius of ≤50 astronomical units. The compactness of the source leaves coronal emission as the most likely scenario. Furthermore, the inferred millimetre-wave and X-ray luminosities follow the Güdel-Benz relationship for stellar coronae. These observations represent the first unambiguous evidence that coronae are the dominant mechanism for centimetre- to millimetre-wave emission in radio-quiet quasars.Item A nuclear spiral in a dusty star-forming galaxy at z = 2.78Stacey, H.R.; Kaasinen, M.; O’Riordan, C.M.; McKean, J.P.; Powell, D.M.; Rizzo, F. (EDP Sciences, 2025-01)The nuclear structure of dusty star-forming galaxies is largely unexplored but harbours critical information about their structural evolution. Here, we present long-baseline Atacama Large (sub-)Millimetre Array (ALMA) continuum observations of a gravitationally lensed dusty star-forming galaxy at z = 2.78. We use a pixellated lens modelling analysis to reconstruct the rest-frame 230 μm dust emission with a mean resolution of ≈55 pc and demonstrate that the inferred source properties are robust to changes in lens modelling methodology. The central 1 kpc is characterised by an exponential profile, a dual spiral arm morphology and an apparent super-Eddington compact central starburst. We find tentative evidence for a nuclear bar in the central 300 pc. These features may indicate that secular dynamical processes play a role in accumulating a high concentration of cold gas that fuels the rapid formation of a compact stellar spheroid and black hole accretion. We propose that the high spatial resolution provided by long-baseline ALMA observations and strong gravitational lensing will give key insights into the formation mechanisms of massive galaxies.Item Tuning optoelectronic properties of CsPbI2Br perovskite films via octadecyl ammonium iodide substitutionThubane, Sandile Job; Nombona, Nolwazi; Diale, M. (Mmantsae Moche) (Springer, 2025-11)Please read abstract in the article.Item A MeerKAT study of a neutral hydrogen rich grouping of galaxies with megaparsec-scale filamentary-like structureLawrie, G.D.; Deane, Roger; Dave, R. (EDP Sciences, 2025-09)CONTEXT. Environmental effects within cosmological overdensities, such as galaxy groups and clusters, have been shown to impact galaxies and their cold gas reservoirs and thereby provide constraints on galaxy evolution models. Galaxy groups foster frequent galaxy-galaxy interactions, making them rich environments in which to study galaxy transformation. AIMS. In this work, we study a serendipitously discovered large overdensity of neutral hydrogen (H I) galaxies at z ∼ 0.04. The galaxies appear to lie in a filamentary-like structure of megaparsec scale. Using MeerKAT’s angular resolution and field of view, we were able to spatially resolve the H I galaxies while simultaneously probing large-scale structure. METHODS. The H I and sub-arcsec Dark Energy Survey (DES) imaging have revealed a large number of both interacting and disturbed galaxies in this collective group. MeerKAT data enabled us to derive H I masses and investigate interacting galaxies. We used DES and Wide-field Infrared Survey Explorer (WISE) data to quantify the star formation rates, stellar masses, and stellar morphologies of member galaxies and compared these with field scaling relations. To place this discovery and the environmental effects in context, we used the SIMBA cosmological hydrodynamical simulation to investigate the prevalence of qualitatively similar H I overdensities and their large-scale morphological properties. This enabled us to make a prediction of how frequently such structures might be serendipitously discovered with MeerKAT and SKA-Mid H I observations in comparable observation time. RESULTS. The combination of spatially resolved H I data and optical imaging revealed a group rich in interactions, suggesting environmental processes are already shaping galaxy properties within the structure. CONCLUSIONS. More of these serendipitous discoveries are expected, and alongside ongoing targeted programmes, they will provide a rich, unbiased sample to study galaxy transformation and enable a MeerKAT H I perspective on large-scale structure, including filaments.Item Electropolymerization of polyaniline on coated activated carbon derived from human hair as a bilayer electrode for supercapacitor applicationsAdam, Rashed Ali Mohamed; Maphiri, Vusani Muswa; Otun, Kabir Opeyemi; Fasakin, Oladepo; Rutavi, Gift; Thior, Souleymane; Manyala, Ncholu I.; Maphiri, Vusani Muswa; Maphiri, Vusani Muswa; Otun, Kabir Opeyemi; Otun, Kabir Opeyemi; Maphiri, Vusani Muswa; Otun, Kabir Opeyemi; Fasakin, Oladepo; Rutavi, Gift; Thior, Souleymane (Elsevier, 2025-09)In this study, electropolymerization was used to deposit polyaniline (PANI) layer on the surface of coated activated carbon derived from human hair (HH-AC) using nickel foam as conducting substrate via cyclic voltammetry (CV) at different cycle numbers. The bilayer HH-AC/PANI electrode was prepared in a non-acidic medium unlike other conventional electrochemical polymerization methods, and characterized using Raman spectroscopy, UV–visible spectroscopy, scanning electron microscope (SEM), and nitrogen physisorption measurements to determine the chemical composition, electronic structure, surface morphology, and textural properties, respectively. The results showed that a PANI layer was successfully deposited on the surface of HH-AC. The electrochemical evaluation was carried out using CV, galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) techniques in 2.5 M KNO3 neutral electrolyte. The optimal bilayer electrode prepared by 8-cycles and denoted as HH-AC/PANI-8 shows an excellent specific capacitance of 220 F g−1 at a positive potential, which is almost twice of 121 F g−1 for that of pristine HH-AC operated in a three-electrode system. Furthermore, for practical application, a symmetric device comprising HH-AC/PANI-8 bilayer electrode was assembled and tested in a two-electrode system configuration, leading to a specific energy of 28.6 W h kg−1 and a specific power of 800W kg−1, at a specific current of 1 A g−1 and voltage window of 1.6 V. Besides, the capacitance retention of the device remained 83 % after 10,000 cycles at 5 A g−1, indicating a long lifespan. These results suggest that the HH-AC/PANI-8 bilayer electrode is a promising candidate for high-performance supercapacitors.Item Investigating biomimetic coatings on Ti-6Al-4V substratesDockrat, Unaisa; Ntsoane, Tshepo Paul; Malherbe, Johan B.; Bam, Lunga Cleartone; Thabethe, Thabsile Theodora (Elsevier, 2025-08)In this in vitro study, medical grade Ti-6Al-4V (Ti64) substrates, approximately 5 mm thick, were immersed in 1.5 × Simulated Body Fluid (SBF) for 56 days to develop biomimetic apatite coatings. Prior to immersion, the substrates underwent surface pretreatment via sandblasting, polishing, and plasma etching. The resulting morphological changes, surface characteristics, crystal structure, phase composition, and mechanical properties were analysed using AFM, SEM, EDS, Micro-CT, and XRD. The findings revealed that surface pretreatment significantly influenced apatite formation. Plasma-etched and sandblasted substrates exhibited more textured and roughened surfaces, which facilitated the formation of denser, more homogeneous coatings compared to the polished substrates. XRD analysis further confirmed the coating to be the hydroxyapatite phase, while AFM measurements demonstrated a notable increase in surface roughness for the sandblasted and plasma-etched samples. Micro CT analysis revealed that while the surface treatments like sandblasting and plasma etching present an interconnected pore structure, the polished surface creates unconnected porosity. These results emphasize the critical role of surface pretreatment in enhancing biomimetic deposition, with implications for improving osseointegration and mechanical compatibility of Ti64-based biomedical implants. HIGHLIGHTS • Ti-6Al-4V (Ti64) substrates were pretreated by sandblasting, polishing, and plasma etching to alter surface morphology. • Substrates were immersed in 1.5 × Simulated Body Fluid (SBF) in vitro for 56 days to develop biomimetic coatings and assess pretreatment effects. • XRD confirmed hydroxyapatite (HAp) on all samples, and SEM analysis showed rougher surfaces on plasma-etched and sandblasted Ti64. • Sandblasting promoted larger HAp crystallites, improving coating structure and potentional mechanical performance.