The Effects and Role of Polyvinylpyrrolidone on the Size and Phase Composition of Iron Oxide Nanoparticles Prepared by a Modified Sol-Gel Method

Table 2

Hyperfine parameters and subspectral areas for the obtained iron oxides.

Sample	Subespect.	(mm/s)	(mm/s)	(mm/s)	(T)	(%)
P6	Sext. H	0.39	0.37	−0.20	51.1	100
P12	Sext. H	0.38	0.37	−0.21	51.2	100
P18	Distrib. M	0.30	0.31	0.00	42.4	20.2
	Sext. H	0.46	0.36	−0.20	50.4	79.8
P24	Distrib. M	0.30	0.31	0.01	47.0	21.1
	Sext. H	0.44	0.41	−0.20	51.1	78.9

: linewidth; : isomer shift; : quadrupole splitting; : hyperfine magnetic field; : area.