Experimental Investigation of the Coprecipitation Method: An Approach to Obtain Magnetite and Maghemite Nanoparticles with Improved Properties

Table 1

Polydispersion index (noted PDI) of magnetite (Mg) and maghemite (MgH) nanoparticles prepared by Procedures 1, 2, and 3.

	Treatment with NaOH 1.5 mol⋅L^−1		Treatment with NH4OH 25%
Sample—Procedure 1	MgP1	MgHP2	MgP3	MgHP4
PDI	0.1645	0.1292	0.0442	0.2446
Sample—Procedure 2	MgP5	MgHP6	MgP7	MgHP8
PDI	0.2669	0.0553	0.1199	0.0754
Sample—Procedure 3	MgP9	MgHP10	MgP11	MgHP12
PDI	0.0256	0.1398	0.1839	0.1599