Large values of isothermal entropy change (Delta S-T) and refrigerant capacity have been found in Gd5Ge2Si2-xSnx compounds. Values of the order of 20 J kg(-1) K-1 for -Delta S-T were obtained in as-cast samples when submitted to a magnetic field variation of 2 T. First-order-magneto-structural transition is induced by the substitution of silicon by tin and it is shifted to lower temperatures with the tin content. It means that the magnetocaloric effect on this series can be properly tuned to a specific practical thermodynamic cycle, including near room temperature range. (C) 2013 AIP Publishing LLC.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo UNIFESP, Inst Ciencia & Tecnol, BR-12231280 Sao Jose Dos Campos, SP, BrazilInst Nacl Metrol Qualidade & Tecnol INMETRO, BR-25250020 Duque de Caxias, RJ, BrazilUniv Estadual Campinas, UNICAMP, Inst Fis Gleb Wataghin, BR-13083970 Campinas, SP, BrazilUniv Fed Vales Jequitinhonha & Mucuri, ICT, BR-39100000 Diamantina, MG, BrazilUniv Estadual Norte Fluminense Darcy Ribeiro UENF, Lab Ciencias Fis, BR-28013602 Campos Dos Goytacazes, RJ, BrazilUniversidade Federal de São Paulo UNIFESP, Inst Ciencia & Tecnol, BR-12231280 Sao Jose Dos Campos, SP, BrazilWeb of Scienc
