Bright field TEM images and corresponding SAED pattern for samples (a) AS40, (b) AC40, (c) IC40, (d) AC5, and (e) HC5 showing Pd NPs having 3.3 ± 0.7 nm and 3.1 ± 0.6 nm diameter in silica and carbon matrixes, respectively. On ions irradiation, Pd NP size increases to 3.9 ± 1.7 nm in sample IC40. In AC5 sample, Pd NPs having smaller (2.8 ± 0.6 nm) size and it increases to 5.7 ± 2.2 nm on hydrogen cycling. The SAED pattern confirms the polycrystalline nature of the Pd NP in the a-carbon and a-silica matrix. 〈D〉 is represented as the average size of nanoparticle.
(a) M-H curve measured using SQUID magnetometer for AS40 and AC40 samples recorded at T = 300 K. The observed value of saturation magnetization (Ms) for the as-deposited Pd NPs in the silica and carbon matrix is also given, and (b) XRD spectra for the AS40 and AC40 samples showing that strain induced by the carbon matrix is higher in comparison to SiO2 matrix in the same size Pd NPs.
The experimental as well as de-convoluted XPS spectrum of core level of (a) Si2p, and (b) Pd 3d5/2 for AS40 and core level of (c) C1s, and (d) Pd3d5/2 for the AC40 sample.
(a) M-H curve measured using SQUID magnetometer for AC40 and IC40 samples is recorded at T = 300 K showing an increase of about 20 times due to defects created on ions irradiation,10 and (b) shows M-H curve for AS40 on ions irradiation, indicating Ms is increased about to 3.5 times due to defects created by ions irradiation.34 The experimental as well as de-convoluted XPS spectra for the core levels of (c) Si2p, and (d) Pd3d5/2 and (e) shows the experimental XPS spectra for the Pd 4d valence band of PdNPs in carbon for the AC40, and IC40, respectively. The valence band centriod shifts 1.33 eV to 1.39 eV for Pd NPs in carbon matrix on ion irradiation.
(a) The hysteresis in the M-H curve obtained using SQUID magnetometry measurements for AC5 and HC5 samples confirms the ferromagnetic behavior of the Pd. Saturation magnetization increased by about 9.3 times on the hydrogenation, and (b) in situ XRD spectrum of the AC5 sample exposed to the hydrogen gas atmosphere a pressure of 1000 mbars for 3 h and on dehydrogenation by evacuation.
The experimental as well as de-convoluted x-ray photoelectron spectra of AC5 and HC5 samples showing (a) C(1 s), (b) Pd (3d5/2) core level, and (c) Pd (4d) valence band spectrum.
Summary of the results on the effect of post deposition treatments on Ms, nanoparticle size, nanoparticle-matrix interface, and defects in NP core and interface.
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