功能材料
功能材料
공능재료
JOURNAL OF FUNCTIONAL MATERIALS
2010年
2期
358-361
,共4页
苏玉玲%黎力%李涛%周云%陈镇平%曹世勋%张金仓
囌玉玲%黎力%李濤%週雲%陳鎮平%曹世勛%張金倉
소옥령%려력%리도%주운%진진평%조세훈%장금창
稀土铬氧化物%倾角反铁磁性%铁磁性%顺磁性
稀土鉻氧化物%傾角反鐵磁性%鐵磁性%順磁性
희토락양화물%경각반철자성%철자성%순자성
rare earth chromites%canted antiferromagnetism(CAFM)%ferromagnetism%paramagnetism
系统研究了稀土ErCrO_3铬氧化物的结构与磁特性,结果表明,室温下实验样品ErCrO_3呈正交的单相结构(Pbnm群);从热磁曲线M-T结合不同温度下的磁滞回线结果发现,在T>133K的高温区体系表现出典型的顺磁特性,其直流磁化率倒数随温度的变化很好地遵从居里-外斯定律,由此拟合可给出体系的有效平均磁矩μ_(eff)=10.57μB、顺磁居里温度T_(cw)=-30K.随温度降低,在133K以下样品呈现出弱铁磁的Г_4(F_x)相,即铁磁相变温度为T_N≈133K;当温度进一步降低到约20K,样品ErCrO_3经历了从Г_4(F_x)弱铁磁到反铁磁相G_y或Г_1(0)的转变,并呈现出自旋重新取向特征;结合ErCrO_3结构特征,这一温度依赖的复杂磁特性反映了Cr~(3+)-Cr~(3+)、Cr~(3+)-Er~(3+)和Er~(3+)-Er~(3+)离子之间的交换耦合作用.
繫統研究瞭稀土ErCrO_3鉻氧化物的結構與磁特性,結果錶明,室溫下實驗樣品ErCrO_3呈正交的單相結構(Pbnm群);從熱磁麯線M-T結閤不同溫度下的磁滯迴線結果髮現,在T>133K的高溫區體繫錶現齣典型的順磁特性,其直流磁化率倒數隨溫度的變化很好地遵從居裏-外斯定律,由此擬閤可給齣體繫的有效平均磁矩μ_(eff)=10.57μB、順磁居裏溫度T_(cw)=-30K.隨溫度降低,在133K以下樣品呈現齣弱鐵磁的Г_4(F_x)相,即鐵磁相變溫度為T_N≈133K;噹溫度進一步降低到約20K,樣品ErCrO_3經歷瞭從Г_4(F_x)弱鐵磁到反鐵磁相G_y或Г_1(0)的轉變,併呈現齣自鏇重新取嚮特徵;結閤ErCrO_3結構特徵,這一溫度依賴的複雜磁特性反映瞭Cr~(3+)-Cr~(3+)、Cr~(3+)-Er~(3+)和Er~(3+)-Er~(3+)離子之間的交換耦閤作用.
계통연구료희토ErCrO_3락양화물적결구여자특성,결과표명,실온하실험양품ErCrO_3정정교적단상결구(Pbnm군);종열자곡선M-T결합불동온도하적자체회선결과발현,재T>133K적고온구체계표현출전형적순자특성,기직류자화솔도수수온도적변화흔호지준종거리-외사정률,유차의합가급출체계적유효평균자구μ_(eff)=10.57μB、순자거리온도T_(cw)=-30K.수온도강저,재133K이하양품정현출약철자적Г_4(F_x)상,즉철자상변온도위T_N≈133K;당온도진일보강저도약20K,양품ErCrO_3경력료종Г_4(F_x)약철자도반철자상G_y혹Г_1(0)적전변,병정현출자선중신취향특정;결합ErCrO_3결구특정,저일온도의뢰적복잡자특성반영료Cr~(3+)-Cr~(3+)、Cr~(3+)-Er~(3+)화Er~(3+)-Er~(3+)리자지간적교환우합작용.
The rare earth ErCrO_3 chromites have been systemically studied by structural and magnetic measurement.The results indicate that the samples show the perovskite-type ErCrO_3 orthorhombic structure with space group Pbnm.The magnetic properties shown that ErCrO_3 possess significant weak ferromagnetism below 133K.At T_(SR)≈20K,ErCrO_3 undergoes a spin reorientation from Г_4(A_x,F_x,C_z) to Г_1(A_x,G_y,C_z) or Г_1(0) where the weak ferromagnetic moment disappears.And in the region of higher temperature T>133K,the reciprocal of magnetic susceptibility χ~(-1) of ErCrO_3 chromites behaves linearly indicating a typical curie-weiss behavior fitted.The effective magnetic moment μ_(eff)=10.57μB and asymptotic paramagnetic curie temperature T_(cw)=-30K,which suggests the predominance of antiferromagnetic interactions in ErCrO_3 chromites.The current magnetization can be interpreted from the interaction between Cr~(3+)-Cr~(3+),Cr~(3+)-Er~(3+),Er~(3+)-Er~(3+).