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系统研究了Nd0．5Ca0．5Mn1-xAlxO3(x=0,0．03)单相多晶样品在低温下的电磁性质和超声特性．电阻和磁化率测量表明,Nd0．5Ca0.5O3体系在TCO-257 K处发生了电荷有序相变．超声声速从室温开始随着温度的降低逐渐减小,并在TCO附近达到最小,之后,随着温度的进一步降低,声速急刷增加,同时伴随着一个尖锐的超声衰减峰出现.TCO附近的超声异常表明体系中存在着强烈的电-声子相互作用,该电-声子耦合来源于Mn3+的Jahn-Teller效应．在低温下,出现了另一个超声衰减峰,它的出现归结为反铁磁相与顺磁相之间的相分离现象.随着Al在Mn位的掺入,超声声速的最低点和衰减峰向低温移动,表明体系中的电荷有序态和反铁磁相均被部分抑制,
The electromagnetic properties and ultrasonic properties of Nd0.5Ca0.5Mn1-xAlxO3 (x = 0,0.03) single-phase polycrystalline samples at low temperature were studied systematically. Resistivity and magnetic susceptibility measurements show that Nd0.5Ca0.5O3 systems undergo charge-order phase transition at TCO-257K. From the room temperature, the sonic velocity decreases gradually with the decrease of temperature and reaches the minimum around the TCO. After that, as the temperature decreases further, the sonic velocity increases sharply accompanied by a sharp ultrasonic attenuation peak. The ultrasound near the TCO Abnormalities indicate that there is a strong electro-phonon interaction in the system, which is derived from the Jahn-Teller effect of Mn3 +. At low temperature, another ultrasonic decay peak appeared, which was attributed to the phase separation between antiferromagnetic phase and paramagnetic phase.With the incorporation of Al in Mn site, the lowest point of ultrasonic velocity and the attenuation peak To the low temperature, indicating that the system of charge state and antiferromagnetic phase are partially inhibited,