Changes on structural and magnetic properties of maghemite nanoparticles during their coverage with MCM-41, Ceramics International, http://dx.doi.org/10.1016/j.ceramint. 2015.08.016 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Mössbauer spectroscopy at 25 and -260 ºC and transmission electron microscopy were used to study the magnetic and structural changes of the initial maghemite nanoparticles produced during its coverage with the mesoporous silica structure. The presence of the mesoporous structure inhibits the expected transformation from maghemite to hematite when the system was calcined in air at 510 ºC. It was established that a sintering of the nanoparticles during the calcination step occurs, leading to a magnetization saturation value similar to that of the bulk compound. In order to evaluate the capability as adsorbent, the magnetic composite was subjected to a surface amino-functionalization and then tested for Cr(VI) and Cu(II) adsorption from water.