Analisis Sruktur dan Sifat Magnetik Manganit Perovskite Nd1-xSrxMnO3 (x = 0; 0,2; 0,4; 0,6; 0,8; 1) dengan Metode Sol-Gel = Structural Analysis and Magnetic Properties of Perovskite Manganite Nd1-xSrxMnO3 (x = 0; 0,2; 0,4; 0,6; 0,8; 1) Using the Sol-Gel Method