Magnetic studies of GaN nanoceramics doped with 1% of cerium

• Published in: Journal of rare earths 2011-12, Vol.29 (12), p.1183-1187
• Main Authors: Oganisian, K., Gluchowski, P., Strek, W.
• Format: Article
• Language: English
• Subjects: Cerium; gallium nitride; Gallium nitrides; magnetism; Magnetization; nanoceramics; Nanocomposites; Nanomaterials; Nanostructure; Rare earth metals; rare earths; Sintering; 压力上升; 摩尔磁化率; 氮化镓; 温度范围; 烧结过程; 纳米陶瓷; 铈离子; 镓掺杂
• ISSN: 1002-0721; 2509-4963
• DOI: 10.1016/S1002-0721(10)60622-9

The magnetization measurements of gallium nitride nanoceramics doped with 1% of cerium and sintered under various pressures were reported. It was found that GaN nanoceramics doped with cerium showed paramagnetic behavior in the wide temperature range. Nanoceramics of GaN with 1% of Ce （as undoped GaN） was diamagnetic one, but under certain temperature the paramagnetic properties started to dominate. This crossover temperature was nonlinearly dependent on the pressure applied during the sintering. The fitting of molar magnetic susceptibility allowed to estimate the Curie temperature, Curie constant and diamagnetic part of susceptibility. As it was found, all the samples showed the antiferromagnetic ordering with θp≈-1 K. Also, the effective magnetic moment was estimated for all of the samples. As a result, magnetic moments in terms of Ce ion were notably larger in comparison with those obtained within the Russell-Saunders cou- pling model. We suggested that it was the strong influence of amorphous shell which was rising with the pressure applied during the sintering. Finally, we presented dependences of magnetization as a function of applied field. All the samples manifested weak ferromagnetism at high temperatures and paramagnetic behavior in low temperature region.