JAEA
  • help
  • PC | SP
  • JP | EN
          
Refine your search：     
Report No.
 - 
Clear All
Search Results: Records 1-3 displayed on this page of 3
  • 1

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Magnetic and structure transition of Mn$$_{3-x}$$Fe$$_x$$O$$_4$$ solid solutions under high-pressure and high-temperature conditions

Yamanaka, Takamitsu*; Hirao, Naohisa*; Nakamoto, Yuki*; Mikouchi, Takashi*; Hattori, Takanori; Komatsu, Kazuki*; Mao, H.-K.*

Physics and Chemistry of Minerals, 49(10), p.41_1 - 41_14, 2022/10

https://doi.org/10.1007/s00269-022-01215-4
 Times Cited Count：0 Percentile：0.02(Materials Science, Multidisciplinary)

Magnetic and crystal structure of Mn$$_{3-x}$$Fe$$_x$$O$$_4$$ solid solutions under high-PT conditions are investigated by neutron diffraction and synchrotron M${"o}$ssbauer spectroscopy. The ferrimagnetic-paramagnetic transition and tetragonal-cubic transition of Mn$$_2$$FeO$$_4$$ spinel occur at 100$$^circ$$C and 180$$^circ$$C, respectively, suggesting both the transitions are not coupled. The structure transition temperature decreases with pressure. M${"o}$ssbauer experiments and neutron diffraction revealed that the Fe$$^{2+}$$ occupancy in tetrahedral site increases increase with pressure, suggesting Mn$$_2$$FeO$$_4$$ phase approaches inverse spinel. Magnetic structure refinement clarified paramagnetic and ferrimagnetic structure of MnFe$$_2$$O$$_4$$ and Mn$$_2$$FeO$$_4$$. These spinels transform into high-pressure orthorhombic phases at 18.4 and 14.0 GPa, respectively, indicating lower transition pressure with increasing Mn content.

Journal Articles

Enhancement of electrical conductivity to metallization of Mn$$_{3-x}$$Fe$$_x$$O$$_4$$ spinel and postspinel with elevating pressure

Yamanaka, Takamitsu*; Rahman, S.*; Nakamoto, Yuki*; Hattori, Takanori; Jang, B. G.*; Kim, D. Y.*; Mao, H.-K.*

Journal of Physics and Chemistry of Solids, 167, p.110721_1 - 110721_10, 2022/08

https://doi.org/10.1016/j.jpcs.2022.110721
 Times Cited Count：1 Percentile：15.7(Chemistry, Multidisciplinary)

High-pressure neutron diffraction proved that MnFe$$_2$$O$$_4$$ and Mn$$_2$$FeO$$_4$$ spinels transform into CaMn$$_2$$O$$_4$$-type structure above 18 GPa and 14 GPa, respectively. The transition pressure of Mn$$_{3-x}$$Fe$$_x$$O$$_4$$ solutions decreases with increasing Mn content. Synchrotron X-ray M$"{o}$ssbauer experiments revealed that Fe$$^{2+}$$ and Fe$$^{3+}$$ distribution at the tetrahedral (A) and octahedral (B) sites in the spinel structure changes with pressure. MnFe$$_2$$O$$_4$$ and Mn$$_2$$FeO$$_4$$ spinels are ferrimagnetic and the CaMn$$_2$$O$$_4$$-type phase is paramagnetic. The temperature dependence of resistivity indicates that both spinels are semiconductors wherein electrons hop between cations at the A and B sites. A pressure-induced shortening of B-B distance promoted conduction via greater electron mobility between adjacent B cations. The Fe$$^{2+}$$ and Fe$$^{3+}$$ occupancies at the B sites in MnFe$$_2$$O$$_4$$ are much larger than those in Mn$$_2$$FeO$$_4$$. The CaMn$$_2$$O$$_4$$-type phase is metallic. Theoretical calculation confirmed the metallic character and Fe d-orbitals strongly renormalized compared to Mn d-orbitals.

Journal Articles

New approach to spin assignments of intermediate structures in $$^{12}$$C($$^{16}$$O,$$^{12}$$C[2$$_1^{+}$$])$$^{16}$$O

Sugiyama, Yasuharu; Tomita, Yoshiaki; Ikezoe, Hiroshi; Yamanouchi, Y.; Ideno, K.; Hamada, S.; Hijiya, M.*; Sugimitsu, Tsuyoshi *; Mukae, T.*; Nakamoto, K.*; et al.

Physical Review C, 49(6), p.3305 - 3308, 1994/06

https://doi.org/10.1103/PhysRevC.49.3305
 Times Cited Count：3 Percentile：18.28(Physics, Nuclear)

no abstracts in English

3 (Records 1-3 displayed on this page)
  • 1