摘要
利用高温固相反应法制备了Eu3+掺杂的Sr2CeO4样品,并对其吸附水前后的光谱特性进行了研究.结果发现,对于刚制备的Sr2-xEuxCeO4+x/2样品,在Ce4+—O2-的电荷迁移激发中,只有强激发带(~35700cm-1)与Eu3+离子间存在能量传递,而弱激发带(~29400cm-1)只是引起Ce4+—O2-的电荷迁移发射;在Sr2-xEuxCeO4+x/2样品吸附水后,Eu3+的线状吸收跃迁强度显著增加,Ce4+—O2-两个激发带均向Eu3+离子传递能量.Ce4+—O2-强激发带通过交换作用向Eu3+离子传递能量,而弱激发带与Eu3+离子间的能量传递机理是非辐射多极子近场力的相互作用.
Eu^3 ＋ doped Sr2CeO4 samples were prepared by a solid-state method and the luminescent properties of the samples with and without adsorbed moisture were investigated. When the Sr2-xEuxCeO4 ＋x/2 samples were prepared, it was found that only the excitation energy in the strong charge-transfer-state （CTS） band of Ce^4＋ -O^2- peaking at about 35700cm^- 1 was transferred to Eu^3 ＋ ion while that in the weak CTS band of Ce^4＋ -O^2- located at about 29400cm^-1 led to Ce^4＋ -O^2- charge-transfer （CT） emission. After adsorption of moisture in the Sr2-xEuxCeO^4＋ x/2 samples, the intensity of Eu^3 ＋ intra-4f^6 absorption transition increased remarkably, the energy transfer took place from the two Ce4＋ --O2- CTS bands to Eu^3＋ ion. The excitation energy in the strong Ce^4＋ -O^2- CTS band was transferred to the Eu^3＋ -O^2- CTS band through radiationless process involving exchange interaction, however, the weak Ce^4＋ -O^2- CTS band caused the excitation to the Eu^3＋ excited levels through resonance radiationless process by a multipole interaction mechanism
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2006年第9期4940-4945,共6页
Acta Physica Sinica
基金
国家自然科学青年基金(批准号:50001010)资助的课题.~~
