TY - JOUR
T1 - The preparation of magnetic iron oxide
AU - Sesigur, H.
AU - Acma, E.
AU - Addemir, O.
AU - Tekin, A.
PY - 1996/12
Y1 - 1996/12
N2 - Two methods for the preparation of magnetic iron oxide starting from FeSO4·TH2O are described. The traditional method involves preparation of Fe(OH)2 seed material, conversion of the seed to acicular γ-FeOOH crystals, dehydration of the crystals to α-Fe2O3, hydrogen reduction of Fe2O3 to magnetite, and finally reoxidation of magnetite particles to γ-Fe2O3. Magnetic iron oxide particles thus obtained, after a total processing time of about 25 h, have a coercivity between 330 and 380 Oe. The other method, known as the direct method, involves fewer steps, a shorter overall processing time, and yields magnetic iron oxide having an equivalent or higher coercivity value. A sample from the seed preparation solution is recrystallized at 250°C, yielding a product, γ-Fe2O3, which has a coercivity value of 320 Oe. In another procedure the seed is prepared in the presence of H2O2 as the oxidizing agent and recrystallized at 300°C for 2 h to yield γ-Fe2O3 having 390 Oe coercivity.
AB - Two methods for the preparation of magnetic iron oxide starting from FeSO4·TH2O are described. The traditional method involves preparation of Fe(OH)2 seed material, conversion of the seed to acicular γ-FeOOH crystals, dehydration of the crystals to α-Fe2O3, hydrogen reduction of Fe2O3 to magnetite, and finally reoxidation of magnetite particles to γ-Fe2O3. Magnetic iron oxide particles thus obtained, after a total processing time of about 25 h, have a coercivity between 330 and 380 Oe. The other method, known as the direct method, involves fewer steps, a shorter overall processing time, and yields magnetic iron oxide having an equivalent or higher coercivity value. A sample from the seed preparation solution is recrystallized at 250°C, yielding a product, γ-Fe2O3, which has a coercivity value of 320 Oe. In another procedure the seed is prepared in the presence of H2O2 as the oxidizing agent and recrystallized at 300°C for 2 h to yield γ-Fe2O3 having 390 Oe coercivity.
KW - A. oxides
KW - D. magnetic properties
UR - http://www.scopus.com/inward/record.url?scp=0030407288&partnerID=8YFLogxK
U2 - 10.1016/S0025-5408(96)00155-9
DO - 10.1016/S0025-5408(96)00155-9
M3 - Article
AN - SCOPUS:0030407288
SN - 0025-5408
VL - 31
SP - 1573
EP - 1579
JO - Materials Research Bulletin
JF - Materials Research Bulletin
IS - 12
ER -