Magnetic properties of Y–Fe–O ultrafine particles containing YFe(3+x)O1.5(4+x) synthesized by rf thermal plasma

Y–Fe–O ultrafine particles containing YFe_(3+x)O_1.5(4+x), -Fe₂O₃, and γ-Fe₂O₃(Fe₃O₄) were fabricated using a thermal plasma evaporation method with rf Ar–O₂. To determine if YFe_(3+x)O_1.5(4+x) in the particles is a ferri-, ferro-, or paramagnetic compound at room temperature (R.T.), the magnetic properties of these particles at R.T. were studied using X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and Mössbauer spectrometry. VSM results showed that the saturation magnetization of particles at R.T. increased after the Curie point (CP) measurement at reduced pressure (4×10⁻³ Pa) from R.T. to an upper limit temperature higher than 460 °C. The saturation magnetization of particles at R.T. after the CP measurement at reduced pressure from R.T. to 700 °C was larger than that from R.T. to 600 °C. In the XRD patterns, the relative quantities of h-YFeO₃ and γ-Fe₂O₃(Fe₃O₄) to that of YFe_(3+x)O_1.5(4+x) increased after the CP measurement at reduced pressure from R.T. to 700 °C, indicating that the saturation magnetization at R.T. increased as the relative quantity of γ-Fe₂O₃(Fe₃O₄) increased. The relative quantities of h-YFeO₃ and γ-Fe₂O₃(Fe₃O₄) to that of YFe_(3+x)O_1.5(4+x) after the CP measurement depended on Fe/Y of the particles, indicating that the increase in saturation magnetization at R.T. after the Curie point measurement depended on the increase in relative quantity of γ-Fe₂O₃(Fe₃O₄). Mössbauer spectrometry before and after the CP measurements showed that YFe_(3+x)O_1.5(4+x) exhibited only a single type of quadrupole splitting and no magnetic splitting, indicating that YFe_(3+x)O_1.5(4+x) is a paramagnetic compound.     

Synthesis, densification and electrical properties of strontium cerate ceramics

Powders of pure and 5% ytterbium substituted strontium cerate (SrCeO₃/SrCe_0.95Yb_0.05O_3−δ) were prepared by spray pyrolysis of nitrate salt solutions. The powders were single phase after calcination in nitrogen atmosphere at 1100 °C (SrCeO₃) and 1200 °C (SrCe_0.95Yb_0.05O_3−δ). Dense SrCeO₃ and SrCe_0.95Yb_0.05O_3−δ materials were obtained by sintering at 1350–1400 °C in air. Heat treatment at 850 and 1000 °C, respectively, was necessary prior to sintering to obtain high density. The dense materials had homogenous microstructures with grain size in the range 6–10 μm for SrCeO₃ and 1–2 μm for SrCe_0.95Yb_0.05O_3−δ. The electrical conductivity of SrCe_0.95Yb_0.05O_3−δ was in good agreement with reported data, showing mixed ionic–electronic conduction. The ionic contribution was dominated by protons below 1000 °C and the proton conductivity reached a maximum of 0.005 S/cm above 900 °C. In oxidizing atmosphere the p-type electronic conduction was dominating above 700 °C, while the contribution from n-type electronic conduction only was significant above 1000 °C in reducing atmosphere.     

Micromechanics of domain switching in rhombohedral PZT ceramics

The lattice strain {2 0 0} and diffraction peak intensity ratio R{1 1 1} have been determined in soft rhombohedral PZT ceramics during the application of an electric field up to 2.5 MV m⁻¹ and as a function of the grain orientation ψ, using high energy synchtron X-ray diffraction. The magnitude of both {2 0 0} and R{1 1 1} increased sharply beyond a field level of 1 MV m⁻¹ due to the onset of ferroelectric domain switching. {2 0 0} exhibited a near linear dependence on cos² ψ, in agreement with previous studies of the remanent-poled state. In contrast, the R{1 1 1}–cos² ψ plot showed evidence of saturation in ferroelectric domain switching, particularly for ψ > 60°. The development of lattice strain during poling is discussed in terms of contributions from the intrinsic piezoelectric effect and from residual stress caused by differences in the poling strain of a grain, and the piezoelectric strain of a grain relative to its surroundings.     

Investigation of some niobate-based dielectrics in view of base metal co-sintering

Bearing in mind the excellent dielectric properties at high frequency of some niobates like ZnNb₂O₆, Zn₃Nb₂O₈, BaNb₂O₆, Ba₅Nb₄O₁₅ (_r 20–45, tan δ < 10 × 10⁻⁴ and ρ_i > 10¹⁰ Ω cm), synthesis, sintering and properties of these oxides are reported. The lowering of their sintering temperature has been investigated for these four ceramics using sintering aids. Using appropriate additive, it is possible to densify these ceramics at a temperature for which base metal electrodes, e.g. Cu and Ag can be employed. Two formulations were found to be sinterable at 1000 °C (lower than the copper melting point) whereas a third formulation is co-sinterable with silver electrodes. For this later, the dielectric properties are globally maintained in comparison with the pure compound sintered at 1200 °C. This result makes this formulation suitable for silver based passive components devices manufacturing.     

Three metal-organic frameworks prepared from mixed solvents of DMF and HAc

Three metal-organic framework compounds [HZn₃(OH)(BTC)₂(2H₂O) (DMF)] · H₂O (MOF-CJ3), [Co₆(BTC)₂(HCOO)₆(DMF)₆] (MOF-CJ4), and [Co₁₈(HCOO)₃₆] · 3H₂O (MOF-CJ5) have been solvothermally synthesized in mixed solvents of DMF and HAc, respectively. These MOFs are characterized by single-crystal X-ray diffraction, X-ray powder diffraction, ICP, TG analyses, IR, and photoluminescence spectroscopy analyses. MOF-CJ3 crystallizes in tetragonal, space group I4cm (No. 108) with a = 20.588(3) Å, b = 20.588(3) Å, c = 17.832(4) Å. Its framework can be described as a 3D decorated (3, 6)-connected net based on the assembly of trigonal prismatic SBUs and triangular links. MOF-CJ4 crystallizes in hexagonal, space group P-3 (No. 147) with a = 13.975(2) Å, b = 13.975(2) Å, c = 8.1650(16) Å. The 2D network of MOF-CJ4 is constructed from [Co₆(R(CO₂)₃)₂(HCO₂)₆(DMF)₆] (R = C₉H₃–) clusters and 1,3,5-benzene-tricarboxylates linkers. MOF-CJ5 crystallizes in triclinic, space group (No. 2) with a = 15.205(3) Å, b = 18.005(4) Å, c = 21.500(4) Å,  = 71.21(3)°, β = 84.47(3)°, γ = 67.15(3)°. MOF-CJ5 has a diamond framework with Co-centered CoCo₄ tetrahedra as nodes. It is noteworthy that the formic ligands in MOF-CJ4 and MOF-CJ5 are generated by the decomposition of DMF under acid conditions and incorporated into these two compounds.     

Low temperature sintering and microwave dielectric properties of 0.5LaAlO3–0.5SrTiO3 ceramics using copper oxide additions

The microwave dielectric properties and the microstructures of 0.5LaAlO₃–0.5SrTiO₃ ceramics with CuO addition prepared with conventional solid-state route have been investigated. Doping with CuO (up to 1 wt.%) can effectively promote the densification and remain comparable dielectric properties of 0.5LaAlO₃–0.5SrTiO₃ ceramics. It is found that 0.5LaAlO₃–0.5SrTiO₃ ceramics can be sintered at 1400 °C due to the sintering aid effect resulted from CuO as addition observed by scanning electron microscopy. The dielectric constant as well as the Q×f value decreases with increasing CuO content. At 1460 °C, 0.5LaAlO₃–0.5SrTiO₃ ceramics with 0.25 wt.% CuO addition possess a dielectric constant (_r) of 35.2, a Q×f value of 24 000 (at 8 GHz) and a temperature coefficient of resonant frequency (τ_f) of −13.5 ppm/°C.     

Nitrogenated nanocrystalline diamond films: Thermal and optical properties

Ultrananocrystalline diamond films have been grown by microwave plasma CVD using CH₄/H₂/Ar mixtures with N₂ added in plasma in amounts up to 25%. The films were characterized with AFM, Raman, XRD, and UV–IR optical absorption spectroscopy mainly focusing on optical and thermal properties. In comparison with polycrystalline CVD diamond the UNCD are very smooth (R_a < 10 nm), have low thermal conductivity ( 0.10 W/cm K), high optical absorption ( 10³ cm^− 1 at 500 nm) and high concentration of bonded hydrogen ( 9 at.%). The nitrogen presence in the plasma has a profound impact on UNCD structure and properties, particularly leading to a decrease in resistivity (by 12 orders of magnitude), thermal conductivity, Tauc band gap, optical transmission and H content. The UNCD demonstrated rather good thermal stability in vacuum: the diamond phase still was present in the films subjected to annealing to 1400 °C.     

Spectroscopic ellipsometry characterization of TiO2 thin films prepared by the sol–gel method

TiO₂ thin films were prepared on SiO₂/Si(100) substrates by the sol–gel process. XRD results indicate that the major phase of TiO₂ thin films is anatase. The surface morphology and cross-section are observed by FE-SEM. The surface of thin films is dense, free of cracks and flat. The average grain size is about 60–100 nm in diameter. The thickness of single layer TiO₂ thin films is about 60 nm, which increases with the concentration of solution. Ellipsometric angles ψ, Δ are investigated by spectroscopic ellipsometry. The optical constant and the thickness of TiO₂ thin films are fitted according to Cauchy dispersion model. The results reveal that the refractive index and the extinction coefficient of TiO₂ thin films in wavelength above 800 nm are about 2.09–2.20 and 0.026, respectively. The influences of processing conditions on the optical constants and thicknesses of TiO₂ thin films are also discussed.     

Phase transition phenomena of the adsorbed 1-dodecanol monolayer at the air–water interface

Phase transition phenomenon of the 1-dodecanol monolayer at the air/water interface was studied by the dynamic γ(t) curves and the adsorption isotherm obtained by ellipsometry at 20 °C. The surface-concentration adsorption isotherm clearly showed three abrupt increases at bulk concentration C of 1.3 × 10⁻⁹, 2 × 10⁻⁹ and 3.7 × 10⁻⁹ mol/mL, respectively. The 1st and the 3rd transitions observed herein, that were typical 2D first-order transitions, were consistent with the gas to liquid expanded (G–LE) and the liquid expanded to liquid condensed (LE–LC) phase transitions observed in a previous tensiometry study. The 2nd transition that occurred at C = 2 × 10⁻⁹ mol/mL was not identified from any previous dynamic surface-tension profiles. Judging from the substantial increase in the film thickness of the transition, it was believed that the orientation change of the adsorbed molecule was involved in the LE phase. A LE_h and a LE_v phase, that denoted the “lie-down” and “stand-up” types of adsorption, respectively, was used to describe this transition and a cusp, instead of a constant surface-tension region, was observed in the dynamic γ(t) curves for this transition. This suggested that, since the surface tension varied during the transition process, the newly identified LE_h and LE_v transition might not be the typical first-order type of phase transition.     

Catalytic performance of Co3O4/CeO2 and Co3O4/CeO2–ZrO2 composite oxides for methane combustion: Influence of catalyst pretreatment temperature and oxygen concentration in the reaction mixture

The influence of catalyst pre-treatment temperature (650 and 750 °C) and oxygen concentration (λ = 8 and 1) on the light-off temperature of methane combustion has been investigated over two composite oxides, Co₃O₄/CeO₂ and Co₃O₄/CeO₂–ZrO₂ containing 30 wt.% of Co₃O₄. The catalytic materials prepared by the co-precipitation method were calcined at 650 °C for 5 h (fresh samples); a portion of them was further treated at 750 °C for 7 h, in a furnace in static air (aged samples).

Tests of methane combustion were carried out on fresh and aged catalysts at two different WHSV values (12 000 and 60 000 mL g⁻¹ h⁻¹). The catalytic performance of Co₃O₄/CeO₂ and Co₃O₄/CeO₂–ZrO₂ were compared with those of two pure Co₃O₄ oxides, a sample obtained by the precipitation method and a commercial reference. Characterization studies by X-ray diffraction (XRD), BET and temperature-programmed reduction (TPR) show that the catalytic activity is related to the dispersion of crystalline phases, Co₃O₄/CeO₂ and Co₃O₄/CeO₂–ZrO₂ as well as to their reducibility. Particular attention was paid to the thermal stability of the Co₃O₄ phase in the temperature range of 750–800 °C, in both static (in a furnace) and dynamic conditions (continuous flow). The results indicate that the thermal stability of the phase Co₃O₄ heated up to 800 °C depends on the size of the cobalt oxide crystallites (fresh or aged samples) and on the oxygen content (excess λ = 8, stoichiometric λ = 1) in the reaction mixture. A stabilizing effect due to the presence of ceria or ceria–zirconia against Co₃O₄ decomposition into CoO was observed.

Moreover, the role of ceria and ceria–zirconia is to maintain a good combustion activity of the cobalt composite oxides by dispersing the active phase Co₃O₄ and by promoting the reduction at low temperature.     

Preparation of rough anatase films and the evaluation of their photocatalytic efficiencies

Sol–gel derived rough anatase films without controlled particle sizes were prepared by surfactant templating. The coating sol–gel was obtained by hydrolysis of Ti(OC₃H₇)₄ in ethanol/HNO₃ solution. The gel films, prepared by dipping glass substrates in surfactant solutions, were dried after immersion under an atmospheric pressure. The rough films of TiO₂ anatase were obtained after calcining at 500 °C. The resultant films were transparent, semitransparent or opaque and 136–402 nm thick. It was found that the TiO₂ films prepared from the sol–gel with surfactant showed a granular nanostructure, and they were composed of regular particles, for example; between 50 and 70 nm. The roughness of the films was found to depend on the surfactant concentration in the sol–gel solution and can show a roughness between 0.82 and near of 17 nm. The photocatalytic activity of the films for the degradation and mineralization of phenol, an industrial pollutant, in water and under 365 nm irradiation was improved by the surfactant modification. Kinetic analysis of degradation and mineralization of phenol in water were employed to evaluate the different TiO₂ films under the same experimental conditions. The global photonic efficiency for degradation and mineralization of phenol ξ_g, was calculated to facilitate comparison with a TiO₂ standard photocatalyst named Degussa P-25.     

Dilute solution properties of carboxymethylchitins in high ionic-strength solvent

The hydrodynamic characteristics in aqueous solution at ionic strength I=0.2  of carboxymethylchitins of different degrees of chemical substitution have been determined. Experimental values varied over the following ranges: the translational diffusion coefficient (at 25.0°C), 1.1<10⁷×D<2.9 cm² s⁻¹; the sedimentation coefficient, 2.4<s<5.0 S; the Gralen coefficient (sedimentation concentration-dependence parameter), 130<k_s<680 mL g⁻¹; the intrinsic viscosity, 130<[η]<550 mL g⁻¹. Combination of s with D using the Svedberg equation yielded ‘sedimentation–diffusion' molecular weights in the range 40 000<M<240 000 g mol⁻¹. The corresponding Mark–Houwink–Kuhn–Sakurada (MHKS) relationships between the molecular weight and s, D and [η] were: [η]=5.58×10⁻³ M^0.94; D=1.87×10⁻⁴ M^−0.60; s=4.10×10⁻¹⁵ M^0.39. The equilibrium rigidity and hydrodynamic diameter of the carboxymethylchitin polymer chain is also investigated on the basis of wormlike coil theory without excluded volume effects. The significance of the Gralen k_s values for these substances is discussed.     

Crystal structure of poly(pentamethylene 2,6-naphthalate)

The crystal structure of poly(pentamethylene 2,6-naphthalate) (PPN) was determined by using X-ray diffraction and molecular modeling. The unit cell of PPN was found to be triclinic ( space group) with dimensions of a=0.457 nm, b=0.635 nm, c=2.916 nm, =121.6°, β=90.4°, γ=87.6°, and the calculated crystal density was 1.311 g cm⁻³. The unit cell contains one polymer chain with two repeating units. In the unit cell, the PPN backbone takes gauche/gauche conformation in the middle part of each pentamethylene unit, and two naphthalene rings are in face-to-face arrangement.     

An FTIR/ATR in situ study of sorption and transport in corrosion protective organic coatings: Paper 2. The effects of temperature and isotopic dilution

A detailed temperature variation (18–50 °C) FTIR/ATR study of sorption and desorption of water into a series of cured epoxy resins has been reported. For higher temperatures (35–50 °C) the data were modelled with a single Fickian diffusion equation, giving an increased D as the temperature increased and an activation energy (E_A) in the 55–60 kJ mol⁻¹ region. At lower temperatures (18–35 °C)—well-below the T_g—a two-stage sorption equation was needed and the apparent E_A was negative. This is probably associated with changes in water clustering among the distributed ‘voids’ in the glassy polymer associated with chain relaxation at extended times. The use of D₂O as a penetrant allowed diffusion coefficient measurements for highly dense epoxy matrices, where FTIR/ATR cannot detect the ν(OH) band of water over and above the residual polymer–OH groups (in the dry state). The data for the D₂O studies were notably influenced by isotopic exchange; which was found to be a diffusion controlled process, even in a polymer matrix.     

Transport numbers and oxygen permeability of SrCe(Y)O3-based ceramics under oxidising conditions

Partial conductivities in the SrCe(Y)O_3−δ system have been studied in oxidising conditions in the temperature range 923–1273 K. Compositions with variable Y content (5 and 10 at.%), Sr deficiency (3 at.%), and with the addition of Fe₂O₃ as sintering aid (2 mol%) were analysed. A modified Faradaic efficiency method and oxygen permeation measurements were employed to appraise the oxide-ionic transport. Oxide-ion transference numbers in air lie in the range 0.19–0.80 and decrease with increasing temperature in the range 973–1223 K. Modelling of total conductivity as a function of oxygen partial pressure (p(O₂)) confirmed that protonic transport is minor under the studied conditions. SrCe_0.95Y_0.05O_3−δ exhibits greater oxide-ion conductivity than SrCe_0.9Y_0.1O_3−δ, indicative of dopant–vacancy association at high dopant contents. Conversely, oxygen permeability is slightly higher for SrCe_0.9Y_0.1O_3−δ as a result of faster surface-exchange kinetics. The oxygen flux through Fe-free membranes is dominated by the bulk in low p(O₂) gradients, when the permeate-side p(O₂) is higher than 0.03 atm, but surface exchange plays an increasing role with increasing p(O₂) gradient. Addition of Fe₂O₃ to SrCe(Y)O_3−δ lowers the sintering temperature by 100 K but results in the formation of intergranular second phases which block oxide-ionic and electronic transport, and thus oxygen permeation. The average thermal expansion coefficients (TECs) are (10.8–11.6) × 10⁻⁶ K⁻¹ in the temperature range 373–1373 K for all studied compositions.     

In situ FTIR characterization of the adsorption of CO and its reaction with NO on Pd-based FCC low NOx combustion promoters

The adsorption of CO and its reaction with NO in the 400–600 °C temperature range on Ceⁿ⁺/Na⁺/γ-Al₂O₃ and Pdⁿ⁺/Ceⁿ⁺/Na⁺/γ-Al₂O₃ type materials used commercially as FCC additives were monitored by FTIR spectroscopy. Exposure of both types of samples to CO leads to the formation of carboxylates and carbonates. The concentration of these species was higher in samples containing Pd, indicating that palladium catalyzes their formation. The Pdⁿ⁺ cations initially present in these samples undergo partial reduction to form metallic Pd in the presence of CO even at room temperature. More complete reduction of Pd, along with some aggregation, was observed after exposure to CO at elevated temperatures. Exposure of both types of samples to NO/CO mixtures in the 400–600 °C temperature range leads to the formation of surface isocyanate species. Both Na⁺ and Ceⁿ⁺ promote the formation of such NCO species. However, surface isocyanate species were formed with substantially higher rates in the presence of palladium. The formation of the isocyanate species strongly correlates with changes observed in the ν_OH region, indicating that hydroxyls actively participate in the surface chemistry involved and are capable of protonating the NCO species. The isocyanates are also reactive towards O₂ and NO yielding CO₂ and N₂. These results suggest that isocyanates are possibly involved as intermediates in the CO–NO reaction over the materials examined.     

Surface modification of polyimide films via plasma polymerization and deposition of allylpentafluorobenzene

Plasma polymerization of allylpentafluorobenzene (APFB) on the plasma-pretreated polyimide (PI) films was carried out. The fluorinated aromatic groups of the plasma-polymerized APFB (pp-APFB) could be preserved, to a large extent, by controlling the glow discharge parameters. The effect of the glow discharge parameters, including the type of the carrier gas and the input RF power, on the surface composition and chemical structure of the pp-APFB films were studied by X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and time-of-flight secondary ion mass spectrometry. The surface topography of the APFB plasma-polymerized PI (pp-APFB-PI) films was studied by atomic force microscopy. For plasma polymerization carried out at a high RF power and using argon as the carrier gas, an ultra-hydrophobic pp-APFB-PI surface was also obtained. The ultra-hydrophobic surface exhibited advancing/receding water contact angles (θ_A/θ_R) of 174°/135°. The effectiveness of the carrier gas in defluorinating the pp-APFB films followed the order of O₂>N₂>H₂>Ar. Thus, the role of the carrier gas in improving the surface hydrophobicity of the resulting pp-APFB-PI films followed the order of O₂22® tape adhesion test.     

Synthesis and characterization of nanocrystalline SrBi2Nb2O9 ferroelectric ceramics using TEA as the polymeric matrix

The processing conditions, reaction mechanism, fine structure of the powders, microstructure, and dielectric properties of SrBiNb₂O₉ (SBN) were systematically studied. A relative density of >80% was obtained using a two-step sintering process at moderate pressure. XRD showed that a single phase with the layered perovskite structure of SrBi₂Nb₂O₉ (SBN) was formed after calcining at 600 °C. No intermediate phase was found during heat treatment at and above 600 °C. The crystallite size (D) and the effective strain (η) were found to be 38.8 nm and 0.01475, respectively, while the particle size obtained from TEM was laid between 25 and 36 nm. SEM revealed that the average grain size after sintering at 900 °C for 4 h was 0.67 μm. Dielectric constant and corresponding tangent loss were measured in the frequency range from 1 kHz to 1 MHz from which the Curie temperature (T_c) was found to be at 450 °C.     

Effect of glass additions on the sintering and microwave properties of composite dielectric ceramics based on BaO–Ln2O3–TiO2 (Ln = Nd, La)

Ten weight percent BBZS (Bi₂O₃, B₂O₃, ZnO and SiO₂) glass was added to x(Ba₄Nd_9.333Ti₁₈O₅₄) − (1 − x)(BaLa₄Ti₄O₁₅) (BNLT, 0 ≤ x ≤ 1) composite dielectric ceramics to lower their sintering temperature whilst retaining microwave properties useful for low temperature co-fired ceramic and antenna core technology. With the addition of 10 wt% BBZS glass, dense BNLT composite ceramics were produced at temperatures between 950 and 1140 °C, depending on composition (x), an average reduction of sintering temperature by 350 °C. X-ray diffraction, scanning and transmission electron microscopy and Raman spectroscopy studies revealed that there was limited inter-reaction between BLT/BNT and the BBZS glass. Microwave property measurement showed that the addition of BBZS glass to BNLT ceramics had a negligible effect on _r and τ_f, although deterioration in the measured quality factor (Qf) was observed. The optimised composition (xBNT − (1 − x)BLT)/0.1BBZS (x = 0.75) had _r  61, τ_f  38 ppm/°C and Qf  2305 GHz.     

Strengthening interfaces between biaxial oriented PET and PSMA: Effects of nitrogen plasma and bonding treatments

The fracture toughness, G_c, of the interface between a nitrogen plasma-treated poly(ethylene terephthalate) (PET) film and a poly(styrene-co-maleic anhydride) (PSMA) substrate was measured by using asymmetric double cantilever beam method. The effects of plasma treatment condition on PET films and post-plasma bonding treatment of the bi-material on the adhesion and the failure mechanism were investigated. For a given plasma pressure and energy, the amount of incorporated nitrogen on the PET surface as determined from X-ray photoelectron spectrometry (XPS) increased with increasing plasma treatment time and reached a plateau value of 7.7 at.%. XPS measurement showed that the incorporated nitrogen was primarily in the form of amine and amide. For bonding temperatures between 130 °C and 160 °C, the fracture toughness increased with increasing nitrogen incorporation on PET surface and reached a saturation G_c which significantly depended on the bonding temperature. The saturation G_c increased from 10 J/m² at 130 °C to 40 J/m² at 140 °C, reached a maximum of 120 J/m² at 150 °C, and then decreased to 60 J/m² at 160 °C. The location of failure also changed drastically with the bonding temperature. SEM and XPS measurements showed that for bonding temperature < 140 °C, failure occurred at the PET/PSMA interface. For bonding temperature = 150 °C, the interfacial adhesion exceeded that of the cohesive strength of PET film and failure occurred within the PET film. At the bonding temperature of 160 °C, failure occurred within PSMA bulk material. XPS measurement was used to measure the areal joint density, Σ_cross of PSMA chains pinned on the functionalized PET film surface. A transition in areal joint density below which G_c scales linear with Σ_cross and above which G_c scales with was found. The transition was identified as the transition from the pure chain scission of in situ formed copolymers to plastic deformation of the interface.