VNU Journal of Science Mathematics – Physics, Vol 37, No 2 (2021) 100 109 100 Original Article Changing the Magnetic Properties of Cobalt Ferrite Nanoparticles with Different Fabrication Conditions Nguyen Ngoc Huyen1, Nguyen Thi Minh Hong1, Pham Duc Thang1, Tran Dang Thanh2, Ho Thi Anh1,* 1VNU University of Engineering and Technology, 144 Xuan Thuy, Cau Giay, Hanoi, Vietnam 2Institute of Materials Science, VAST, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam Received 22 April 2020 Revised 28 Aug[.]