Magical superconducting materials

Superconducting materials are materials without resistance, which can save energy, reduce the energy consumed by electrical energy due to resistance, and store current for use when it is urgently needed. Since the world's electricity as the main driving force, it has encountered two headaches, one is that when the current is transmitted, a lot of electricity is heated due to the resistance of the wire, and a considerable amount of energy is lost in vain. Another problem is that the power during the day is often seriously insufficient, and the late night power is greatly surplus, so that the generator is often overloaded during the day, but idle in the middle of the night, and the power is wasted. Can you store the surplus electricity at night to make up for the lack of electricity during the day?

A difficult journey

Ever since the advent of superconducting materials, there is great hope for solving this problem. How are superconducting materials discovered? It was 1911, and many scientists had discovered that the resistance of a metal had a lot to do with its temperature conditions. When the temperature is high, its resistance increases, and when the temperature is low, the resistance decreases. And summarize a theoretical formula for the relationship between metal resistance and temperature. At this time, the Dutch physicist Onnis tested whether this theoretical formula was correct, and tested mercury. When he cooled the mercury to -40 °C, the shiny liquid mercury became solid like "frozen", and then he pulled the mercury into filaments and continued to lower the temperature. Measuring the resistance of solid mercury at different temperatures at the same time, when the temperature dropped to 4K, a strange phenomenon occurred, and the resistance of mercury suddenly became zero. At first he didn't quite believe the results, so he tried again and again, but it was the same. This discovery caused a sensation in the world's physics community, and later scientists called this phenomenon superconductivity, the material with a resistance equal to zero called superconducting material, and the temperature at which superconductivity occurred was called the "critical temperature" of superconducting materials.

Onnis and many scientists later discovered 28 superconducting elements and more than 8,000 superconducting compound materials. But the critical temperatures at which superconductivity occur mostly at extremely low temperatures close to absolute zero, which have little economic value, because manufacturing such extremely low temperatures is inherently expensive and difficult.

In order to find materials without resistance with relatively high critical temperatures, countless scientists around the world have struggled for nearly 60 years and have not made much progress. It was not until 1973 that some scientists in britain and the United States found a niobium-germanium alloy that superconducted at 23K. This record has since been maintained for more than 10 years.

In 1986, Bettnots and Müller, who worked in the laboratory of the Swiss International Commercial Company, learned from the many failures of others, abandoned the old concept of looking for superconducting materials in metals and alloys, emancipated their minds, and finally discovered that a lanthanum copper barium oxide ceramic oxide material superconductivity phenomenon appears at a higher temperature of 43K. This was a remarkable achievement, so both of them won the 1987 Nobel Prize in Physics at the same time.

Since then, Chinese-American scholar Zhu Jingwu and Chinese physicist Zhao Zhongxian have successively discovered in 1987 that yttrium barium copper oxygen high-temperature superconducting materials that have superconductivity phenomena at 78.5K and 98K. Soon it was found that strontium calcium-oxygen copper high-temperature superconducting alloy, at a temperature of 110K there is a superconductivity phenomenon; The superconducting temperature of the thallium barium-barium calcium copper-oxygen alloy found later is closer to room temperature, reaching 120K. In this way, the superconducting material can work in liquid nitrogen. This can be said to be a major breakthrough in science and technology in the 20th century, and it is also a new milestone in the history of the development of superconducting technology.

To this day, research on high-temperature superconducting materials is still in the ascendant. In 1991, scientists in the United States and Japan discovered that the spherical carbon molecule C-60 is also superconducting after being mixed with potassium, cesium, neodymium and other elements. Some scientists anticipate that after the spherical carbon molecule C-60 is metal-doped, it is possible to appear superconducting at room temperature in the future, when superconducting materials may cause an industrial and technological revolution in the world like semiconductor materials.