ArticleTác giả : Truong, Thanh Trung; Do, Thi Nhung; Nguyen, Thi Thanh Van; Nguyen, Hoang Nam; Nguyen, Hoang Luong (2016)
CoxPt100- x nanoparticles (x=50, 59, and 73) were prepared by the chemical reduction of Cobalt (II)
chloride and Chloroplatinic acid, then ultrasonicated for 2 h. After annealing at various temperatures
from 450 C to 700 C for 1 h, structure change was observed and samples show hard magnetic prop-erties which depend strongly on chemical composition and annealing temperature. The highest coer-civity value of 1.15 kOe was obtained at room temperature for sample with x =50 annealed at 500 C. Chemical reduction combined with ultrasound is a useful method to prepare CoPt nanoparticles 
