Charge and spin order in the perovskite CaF e 0.5 M n 0.5 O 3 : Charge disproportionation behavior of randomly arranged F e 4 +
Charge and spin order in the perovskite CaF e 0.5 M n 0.5 O 3 : Charge disproportionation behavior of randomly arranged F e 4 +
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DOI：
10.1103/physrevb.94.104429
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发表时间：
2016-09
影响因子：
3.7
通讯作者：
Yoshiteru Hosaka;N. Ichikawa;Takashi Saito;J. Attfield;Y. Shimakawa
中科院分区：
文献类型：
--
作者：
Yoshiteru Hosaka;N. Ichikawa;Takashi Saito;J. Attfield;Y. Shimakawa
$B$-site-disordered perovskite $\mathrm{CaF}{\mathrm{e}}_{0.5}\mathrm{M}{\mathrm{n}}_{0.5}{\mathrm{O}}_{3}$ with unusually high valence $\mathrm{F}{\mathrm{e}}^{4+}$ was synthesized using a high-pressure technique. $\mathrm{F}{\mathrm{e}}^{4+}$ randomly distributed at half of the $B$ sites shows charge disproportionation to $\mathrm{F}{\mathrm{e}}^{3+}$ and $\mathrm{F}{\mathrm{e}}^{5+}$. The spins of $\mathrm{F}{\mathrm{e}}^{3+},\phantom{\rule{0.16em}{0ex}}\mathrm{F}{\mathrm{e}}^{5+}$, and $\mathrm{M}{\mathrm{n}}^{4+}$ order below 90 K. Analysis of low-temperature neutron powder-diffraction data revealed a $G$-type antiferromagnetic structure\char22{}where all the nearest-neighboring spins of $\mathrm{F}{\mathrm{e}}^{3+},\phantom{\rule{0.16em}{0ex}}\mathrm{F}{\mathrm{e}}^{5+}$, and $\mathrm{M}{\mathrm{n}}^{4+}$ couple antiparallel\char22{}and the small ordered moment of $0.58\phantom{\rule{0.16em}{0ex}}{\ensuremath{\mu}}_{\mathrm{B}}$ reveals local charge ordering that gives rise to predominant $\mathrm{F}{\mathrm{e}}^{3+}$-O-$\mathrm{F}{\mathrm{e}}^{5+}$ antiferromagnetic arrangements. Despite the identical chemical compositions of $\mathrm{CaF}{\mathrm{e}}_{0.5}\mathrm{M}{\mathrm{n}}_{0.5}{\mathrm{O}}_{3}$ and $\mathrm{C}{\mathrm{a}}_{2}\mathrm{FeMn}{\mathrm{O}}_{6}$, the magnetic structure of the present $\mathrm{CaF}{\mathrm{e}}_{0.5}\mathrm{M}{\mathrm{n}}_{0.5}{\mathrm{O}}_{3}$ is very different from the noncollinear one of layered $B$-site-ordered $\mathrm{C}{\mathrm{a}}_{2}\mathrm{FeMn}{\mathrm{O}}_{6}$.
$B$-site-disordered perovskite $\mathrm{CaF}{\mathrm{e}}_{0.5}\mathrm{M}{\mathrm{n}}_{0.5}{\mathrm{O}}_{3}$ with unusually high valence $\mathrm{F}{\mathrm{e}}^{4+}$ was synthesized using a high-pressure technique. $\mathrm{F}{\mathrm{e}}^{4+}$ randomly distributed at half of the $B$ sites shows charge disproportionation to $\mathrm{F}{\mathrm{e}}^{3+}$ and $\mathrm{F}{\mathrm{e}}^{5+}$. The spins of $\mathrm{F}{\mathrm{e}}^{3+},\phantom{\rule{0.16em}{0ex}}\mathrm{F}{\mathrm{e}}^{5+}$, and $\mathrm{M}{\mathrm{n}}^{4+}$ order below 90 K. Analysis of low-temperature neutron powder-diffraction data revealed a $G$-type antiferromagnetic structure\char22{}where all the nearest-neighboring spins of $\mathrm{F}{\mathrm{e}}^{3+},\phantom{\rule{0.16em}{0ex}}\mathrm{F}{\mathrm{e}}^{5+}$, and $\mathrm{M}{\mathrm{n}}^{4+}$ couple antiparallel\char22{}and the small ordered moment of $0.58\phantom{\rule{0.16em}{0ex}}{\ensuremath{\mu}}_{\mathrm{B}}$ reveals local charge ordering that gives rise to predominant $\mathrm{F}{\mathrm{e}}^{3+}$-O-$\mathrm{F}{\mathrm{e}}^{5+}$ antiferromagnetic arrangements. Despite the identical chemical compositions of $\mathrm{CaF}{\mathrm{e}}_{0.5}\mathrm{M}{\mathrm{n}}_{0.5}{\mathrm{O}}_{3}$ and $\mathrm{C}{\mathrm{a}}_{2}\mathrm{FeMn}{\mathrm{O}}_{6}$, the magnetic structure of the present $\mathrm{CaF}{\mathrm{e}}_{0.5}\mathrm{M}{\mathrm{n}}_{0.5}{\mathrm{O}}_{3}$ is very different from the noncollinear one of layered $B$-site-ordered $\mathrm{C}{\mathrm{a}}_{2}\mathrm{FeMn}{\mathrm{O}}_{6}$.