Cargando…

Hard magnetic ferrite with a gigantic coercivity and high frequency millimetre wave rotation

Magnetic ferrites such as Fe(3)O(4) and Fe(2)O(3) are extensively used in a range of applications because they are inexpensive and chemically stable. Here we show that rhodium-substituted ε-Fe(2)O(3), ε-Rh(x)Fe(2−x)O(3) nanomagnets prepared by a nanoscale chemical synthesis using mesoporous silica a...

Descripción completa

Detalles Bibliográficos
Autores principales: Namai, Asuka, Yoshikiyo, Marie, Yamada, Kana, Sakurai, Shunsuke, Goto, Takashi, Yoshida, Takayuki, Miyazaki, Tatsuro, Nakajima, Makoto, Suemoto, Tohru, Tokoro, Hiroko, Ohkoshi, Shin-ichi
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Pub. Group 2012
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3658006/
https://www.ncbi.nlm.nih.gov/pubmed/22948817
http://dx.doi.org/10.1038/ncomms2038
Descripción
Sumario:Magnetic ferrites such as Fe(3)O(4) and Fe(2)O(3) are extensively used in a range of applications because they are inexpensive and chemically stable. Here we show that rhodium-substituted ε-Fe(2)O(3), ε-Rh(x)Fe(2−x)O(3) nanomagnets prepared by a nanoscale chemical synthesis using mesoporous silica as a template, exhibit a huge coercive field (H(c)) of 27 kOe at room temperature. Furthermore, a crystallographically oriented sample recorded an H(c) value of 31 kOe, which is the largest value among metal-oxide-based magnets and is comparable to those of rare-earth magnets. In addition, ε-Rh(x)Fe(2−x)O(3) shows high frequency millimetre wave absorption up to 209 GHz. ε-Rh(0.14)Fe(1.86)O(3) exhibits a rotation of the polarization plane of the propagated millimetre wave at 220 GHz, which is one of the promising carrier frequencies (the window of air) for millimetre wave wireless communications.