Resumen: A numerically solved two-level Stoner-Wohlfarth model with thermal agitation is used to simulate Zero Field Cooling (ZFC)-Field Cooling (FC) curves of monosize and polysize samples and to determine the best method for obtaining a representative blocking temperature TB value of polysize samples. The results confirm a technique based on the T derivative of the difference between ZFC and FC curves proposed by Micha et al. (the good) and demonstrate its relation with two alternative methods: the ZFC maximum (the bad) and the inflection point (the ugly). The derivative method is then applied to experimental data, obtaining the TB distribution of a polysize Fe3O4 nanoparticle sample suspended in hexane with an excellent agreement with TEM characterization. Idioma: Inglés DOI: 10.1063/1.4935484 Año: 2015 Publicado en: Journal of Applied Physics 118, 18 (2015), 400382 ISSN: 0021-8979 Factor impacto JCR: 2.101 (2015) Categ. JCR: PHYSICS, APPLIED rank: 47 / 145 = 0.324 (2015) - Q2 - T1 Factor impacto SCIMAGO: 0.821 - Physics and Astronomy (miscellaneous) (Q2)