Piezoelectricity

Piezoelectric Effect

压电效应

Crystals which acquire a charge when compressed, twisted or distorted are said to be piezoelectric. This provides a convenient transducer effect between electrical and mechanical oscillations. Quartz demonstrates this property and is extremely stable. Quartz crystals are used for watch crystals and for precise frequency reference crystals for radio transmitters. Rochelle salt produces a comparatively large voltage upon compression and was used in early crystal microphones. Barium titanate, lead zirconate, and lead titanate are ceramic materials which exhibit piezoelectricity and are used in ultrasonic transducers as well as microphones. If an electrical oscillation is applied to such ceramic wafers, they will respond with mechanical vibrations which provide the ultrasonic sound source. The standard piezoelectric material for medical imaging processes has been lead zirconate titanate (PZT). Piezoelectric ceramic materials have found use in producing motions on the order of nanometers in the control of scanning tunneling microscopes.

当晶体被压缩、扭曲或变形时会获得电荷，这类晶体被称为压电的。这为电学振荡与机械振荡之间提供了一个方便的转换效应。石英表现出这种性质，并且非常稳定。石英晶体用于手表和无线电发射机的精确频率参考晶体。罗切斯特盐在压缩时会产生相对较大的电压，并曾用于早期的晶体麦克风。钛酸钡、铅锆酸盐和铅钛酸盐是陶瓷材料，表现出压电性，并且被用于超声波换能器以及麦克风中。如果将电学振荡施加到这样的陶瓷薄片上，它们会产生机械振动，从而提供超声波声源。医疗成像过程中标准的压电材料是铅锆钛酸盐（PZT）。压电陶瓷材料已被用于产生纳米级的运动，以控制扫描隧道显微镜。

The word piezo is Greek for "push". The effect known as piezoelectricity was discovered by brothers Pierre and Jacques Curie when they were 21 and 24 years old in 1880.

‘Piezo’这个词源自希腊语，意为‘推’。压电效应是由21岁和24岁的兄弟皮埃尔和雅克·居里于1880年发现的。

There is a magnetic analog where ferromagnetic materials respond mechanically to magnetic fields. This effect, called magnetostriction, is responsible for the familiar hum of transformers and other AC devices containing iron cores.

存在一种磁学类比，铁磁性材料会对磁场产生机械响应。这种现象称为磁致伸缩，是变压器及其他含有铁芯的交流设备发出熟悉嗡嗡声的原因。

Scanning Tunneling Microscope

扫描隧道显微镜

The subject of a 1986 Nobel Prize, the scanning tunneling microscope is currently the most powerful and versatile tool for imaging individual atoms. If a pointed metal probe is placed sufficiently close to a solid sample and a voltage of say 10 millivolts is applied between the probe and the surface, then electron tunneling can occur. The separation between the mini-tip of the probe and the sample must be on the order of nanometers. The exponential variation of the tunneling current with separation can show surface variations in the range 0.01 nanometers. The sharpening of the mini-tip of the probe is accomplished with electrochemical etching. This etching sharpens it to only about 1000 nm, but since the sharpening is not perfectly smooth, it leaves a surface with many mini-tips which are on the scale of nanometers.

1986年诺贝尔奖的获奖主题，扫描隧道显微镜目前是用于成像单个原子最强大且最灵活的工具。如果将一个尖锐的金属探针足够接近固体样品，并在探针和样品之间施加约10毫伏的电压，那么电子隧道效应就会发生。探针的微型尖端与样品之间的距离必须在纳米范围内。隧道电流随距离的指数变化可以显示0.01纳米范围内的表面变化。探针的微型尖端通过电化学蚀刻来 sharpen。这种蚀刻将尖端 sharpen 到约1000纳米，但由于 sharpen 不是完全平滑，它会在表面上留下许多微型尖端，这些尖端的尺度在纳米范围内。

Positioning a probe over the nanometer range can be done with piezoelectric ceramic wafers.

Gert Binnig and Heinrich Rohrer were awarded the Nobel Prize in 1986 along with Ernst Ruska for his work in developing electron microscopy.

格特·比内格和海因里希·罗赫尔因在发展电子显微镜方面的贡献，于1986年与恩斯特·鲁斯卡共同获得诺贝尔奖。

使用压电陶瓷片可以在纳米范围内对探针进行定位。