Magnetoelectric Effects in Ferromagnetic Oxides with the Double Perovskite Structure
Magnetoelectric Effects in Ferromagnetic Oxides with the Double Perovskite Structure
批准号:
18540342
负责人:
ASAI Kichizo
金额:
$2.45万
依托单位国家:
日本
项目类别:
Grant-in-Aid for Scientific Research (C)
财政年份:
2006
资助国家:
日本
项目状态:
已结题
起止时间:
2006 至 2007
中文摘要
本文用X射线衍射、磁、电测量和~ 1HNMR研究了La_ Bi_xMn_ Ni_ O_3的晶体结构和磁介电性质,铁磁性和铁电性的竞争,以及磁电效应<1-x><0.5><0.5><55>。(1)采用<1-x><0.5><0.5>软化学合成法在常压下成功地合成了具有双钙钛矿结构的La_ Bi_xMn_ Ni_ O_3多晶(x=0 ~ 0.9)。随着x的增加,介电常数增加,铁磁居里温度(T_<CM>)降低. (2)通过<55>REMn_<0.5>(Ni_<1-x>Mg_x)_<0.5>Ni_<0.5>O_3(RE =稀土元素)中~(40)Mn的NMR研究,阐明了在~(40)Mn处,<2->由超精细磁场H_估算出双钙钛矿中Mn^<4+>-O^ -Ni^<2+>键<HF>的共价参数f(RE)<55>。在此基础上,得到了La_ Bi_xMn_ Ni_ Ni_ O_3中键的共价参数f(x)<1-x><0.5><0.5><0.5>为 关于我们 通过<55>对氧化物的~ 1 Mn NMR研究发现,随着x的增加,氧化物的还原性降低。f<CM>(x)的降低是由于Bi^<3+>-O^^键的共价性比<2->La^<3 +>-O ^<2->键强,O^离子的电子更多<2->地被吸引到Bi^<3+>-O ^键中,从而<2->导致Mn^<4+>-O^<2->-Ni^<2+>键中的电子不足。Bi^<3+>-O^键的共价性所产生的铁电性<2->和Mn^<4+>-O^<2->-Ni^<2+>键的铁磁性通过两个键的共价性的竞争而相互竞争。(3)当x ≥ 0.5时,在磁场T_附近,介电常数增大<CM>.当x=0.7时,在9 T时,介电常数增加了7%<CM>.基于Maxwell-Wagner模型解释了介电常数的温度和磁场依赖性,包括频率色散,该模型假设样品的不均匀性,该样品包含分散在具有负磁阻的材料中的具有相对高介电常数的畴。少
英文摘要
We have investigated (1) the crystal structure and the magnetic-dielectric properties, (2) competition of the ferromagnetism and ferroelectricity, and (3) the magnetoelectric effects of La_<1-x>Bi_xMn_<0.5>Ni_<0.5>O_3 by means of the x-ray diffraction, magnetic and electric measurements, and ^<55>Mn NMR.(1) Polycrystalline La_<1-x>Bi_xMn_<0.5>Ni_<0.5>O_3 with the double perovskite structure has been successfully synthesized for x=0〜0.9 by soft chemical synthesis at ambient pressure. The dielectric constant increases and the ferromagnetic Curie temperature (T_<CM>) decreases with increasing x.(2) It has been clarified through NMR of ^<55>Mn in REMn_<0.5>(Ni_<1-x>Mg_x)_<0.5>Ni_<0.5>O_3 (RE = rare earth elements) that the covalency parameter, f(RE), for Mn^<4+>-O^<2->-Ni^<2+> bond in the double perovskite is evaluated from the hyperfine magnetic field, H_<HF>, at ^<55>Mn. Based on the knowledge, the covalency parameter, f (x), for the bond in La_<1-x>Bi_xMn_<0.5>Ni_<0.5>Ni_<0.5>O_3 is fou … More nd to decrease with increasing x by ^<55>Mn NMR study of the oxides. The decrease of T_<CM> with increasing xis naturally explained with the decrease of f(x).The decrease of f (x) is attributed to the strong covalency of Bi^<3+>-O^<2-> bond compared with La^<3+>-O^<2-> bond; more electrons of O^<2-> ions are attracted to and populate in Bi^<3+>-O^<2-> bond resulting in deficiency of electrons in Mn^<4+>-O^<2->-Ni^<2+> bond. The ferroelectricity arising from the covalency of Bi^<3+>-O^<2-> bond and the ferromagnetism arising from that of Mn^<4+>-O^<2->-Ni^<2+> bond compete with each other through the competition of the covalencies of both bonds.(3) For x≧0.5, the dielectric constant increases in a magnetic field near T_<CM>. For x=0.7, the increment of the dielectric constant amounts to 7% at T_<CM> in 9 T. The temperature and the magnetic field dependence of the dielectric constant, including the frequency dispersion, has interpreted based on the Maxwell-Wagner model assuming an inhomogeneity of the sample which contains domains with relatively high dielectric constant dispersed in the material with negative magneto-resistance. Less
期刊论文(0)
专著(0)
科研奖励(0)
会议论文
登录
查看更多内容
La_<1-x> Bi_xMn_<0. 5> Ni_<0. 5> O_3の<55>^Mn NMR
La_<1-x>Bi_xMn_<0>Ni_<0>O_3<55>^Mn NMR。
DOI:
--
发表时间:
2009
期刊:
影响因子:
--
作者:
[河内良行, 小山佳一, 晴被宏大, 田中遼司, 戎修二, 永田正一, I. V. Solovyev, 戎修二, 浅井吉蔵,川上貴史,榎下峻平,鴨川征史,塩沢正規,小林義彦]
通讯作者:
浅井吉蔵,川上貴史,榎下峻平,鴨川征史,塩沢正規,小林義彦
Crystal Structure, Magnetism, and Dielectric Properties of La1-xBixNi0.5Mn0.5O3
La1-xBixNi0.5Mn0.5O3 的晶体结构、磁性和介电性能
DOI:
10.1143/jpsj.77.084701
发表时间:
2008
期刊:
Journal of the Physical Society of Japan
影响因子:
1.7
作者:
[Y. Kobayashi, M. Shiozawa, Keisuke Sato, K. Abe, K. Asai]
通讯作者:
K. Asai
Ba_<1-x>Sr_xRuO_3の結晶構造と磁性・電子輸送現象
Ba_<1-x>Sr_xRuO_3的晶体结构、磁性和电子输运现象
DOI:
--
发表时间:
2007
期刊:
影响因子:
--
作者:
[金子徹也, 小林義彦, 浅井吉蔵]
通讯作者:
浅井吉蔵
Hyperfine Magnetic Field at ^55Mn in Ferromagnetic Perovskites REMn_<0.5>(Ni_<1-x>Mg_x)_<0.5>O_3 with RE = La, Pr, Nd, and Eu : RE Dependence of Supertransferred Hyperfine Interaction.
铁磁钙钛矿 REMn_<0.5>(Ni_<1-x>Mg_x)_<0.5>O_3 中 ^55Mn 处的超精细磁场,其中 RE = La、Pr、Nd 和 Eu:超转移超精细相互作用的 RE 依赖性。
DOI:
--
发表时间:
2008
期刊:
J. Phys. Soc. Jpn. 77
影响因子:
--
作者:
[T. Kawakami, S. Enoshita, M. Kamogawa, Y. Kobayashi, K. Asai]
通讯作者:
K. Asai
High-Field Magnetostriction of the Spin-State Transition Compound LaCoO_3
自旋态过渡化合物LaCoO_3的高场磁致伸缩
DOI:
--
发表时间:
2008
期刊:
J. Phys. Soc. Jpn. 77
影响因子:
--
作者:
[T. Kawakami, S. Enoshita, M. Kamogawa, Y. Kobayashi, K. Asai, M. Matsukawa, K. Sato等]
通讯作者:
K. Sato等
共 19 条
Investigation of the Spin-Phase Separation in LaCoO3 by High-field Magnetization
-
批准号:24540365
-
项目类别:Grant-in-Aid for Scientific Research (C)
-
资助金额:$3.24万
-
财政年份:2012
-
负责人:ASAI Kichizo
-
依托单位:
Study on the Anomalous Magnetoelectric Effect of Yttrium Iron Garnet by 57Fe NMR
-
批准号:20540332
-
项目类别:Grant-in-Aid for Scientific Research (C)
-
资助金额:$3.0万
-
财政年份:2008
-
负责人:ASAI Kichizo
-
依托单位:
Phonon study by neutron scattering on the orbital-order of the intermediate-spin-state of Co^<3+> and the spin-state transition
-
批准号:16540310
-
项目类别:Grant-in-Aid for Scientific Research (C)
-
资助金额:$2.37万
-
财政年份:2004
-
负责人:ASAI Kichizo
-
依托单位:
Lattice anomaly associaterd with the magnetic order in a re-entrant superconductor Ho_<1-x>Y_xNi_2B_2C
-
批准号:14540331
-
项目类别:Grant-in-Aid for Scientific Research (C)
-
资助金额:$1.92万
-
财政年份:2002
-
负责人:ASAI Kichizo
-
依托单位:
Study on Spin-State Transitions in LaCoO_3
-
批准号:08640449
-
项目类别:Grant-in-Aid for Scientific Research (C)
-
资助金额:$1.41万
-
财政年份:1996
-
负责人:ASAI Kichizo
-
依托单位:
海外基金