1：Experimental Design and Method Selection:

The study uses femtosecond laser ablation in liquid (LAL) to produce iron nanoparticles (FeNPs) without toxic chemicals, followed by nanosecond pulsed laser deposition (PLD) to deposit thin films. The rationale is to create biocompatible coatings with magnetic properties for orthopedic implants.

2：Sample Selection and Data Sources:

A Fe foil (

3：9% purity) is ablated in bidistilled water to produce FeNPs, which are mixed with commercial hydroxyapatite powder to form a composite target. Films are deposited on monocrystalline silicon substrates. List of Experimental Equipment and Materials:

Spectra Physics SpitfirePro Ti:Sapphire laser (λ: 800 nm, τ: 120 fs, repetition rate: 1 kHz, E: 3 mJ), doubled Nd:YAG pulsed laser (λ: 532 nm, τ: 10 ns, repetition rate: 10 Hz, fluence: 37 J cm?2), hydrostatic press (10 tons), vacuum chamber (working pressure: 4×10?? Pa), optical emission spectroscopy setup with spectrograph and ICCD, TEM (HRTEM Fei-TECNAI G2 20 TWIN), XRD (X-Perth-Pro Philips), Micro-Raman (Jobin-Yvon Horiba LabRam), FT-IR (Jasco FT-IR 460 Plus), SEM (Philips-FEI ESEM XL30), AFM (Park System XE 120), SQUID magnetometer (Quantum Design). Materials include Fe foil (Aldrich), hydroxyapatite powder (Sigma-Aldrich), bidistilled water, silicon substrates (Goodfellow).

4：Experimental Procedures and Operational Workflow:

LAL is performed by focusing the femtosecond laser on the Fe foil submerged in water, with centrifugation to collect FeNPs. The composite target is pressed and used in PLD with the nanosecond laser in a vacuum chamber at substrate temperatures of RT, 300°C, and 500°C for 4 hours. Characterization involves TEM, XRD, Raman, FT-IR, SEM, AFM, and magnetic measurements.

5：Data Analysis Methods:

Data are analyzed using techniques such as FFT for TEM images, Boltzmann plot for plasma temperature, and statistical methods for surface roughness and magnetic properties.