For the past few years, we frequently hear of "the rare metal problem" or "the rare metal crisis". The terminology, "rare metal", is not an academically defined one, and there is no consensus on which element it pertains. In Japan, recently, the term is often used to refer to the 47 metal elements shown in Figure 1, according to the definition set by the Ministry of Economy, Trade and Industry. Sometimes, the 17 rare earth elements are counted as one kind, and the total is counted as 31. There are a total of 89 existing elements in the natural world, and therefore, it can be said that over half of the elements are rare metals.

Elements as titanium, manganese, chromium, which are found in abundance in the earth's crust, are also considered to be rare metals. This is because manganese and chromium have been essential elements for the industrial world since its early days, used as additives to enhance the properties of iron. Titanium is considered "rare" because it is a difficult metal to produce as high technology is required for refining the abundant ore in form of titanium oxide. On the other hand, from historical circumstances, gold and silver, which have been in existence since ancient times, are not called rare metals.

Rare metals have been called "vitamins of industry" and their importance in industry has been recognized for some time. However, recently, the industry has become highly dependant on products that can not be made without using rare metals so that they are becoming "the lifeline of industry".

Here are introduced some representative examples of products in which rare metals play important roles, or in which they will do so in the near future.

Figure 2 shows the relationship between rare metals and the automobiles of today as well as the energy-saving cars with low environmental load presently being developed. It is evident that no matter what type of automobile is developed, rare metals will become more and more important.

Another example is liquid crystal television. The production of liquid crystal television is rapidly growing and its screen is getting larger and larger. An extremely rare metal, indium, is indispensable as an element of the transparent conductive film (ITO) of liquid crystal television panel.

Although the importance of rare metals is increasing, the supply is not necessarily stable and the prices are recently rising sharply which causes a big problem. The points that follow can be considered as its international background.

Such phenomena as the globalization of the economy and the development of modularized products have made possible the explosive increase of the productivity of many products. This also heightens the danger of sudden demand-supply imbalance in rare metal markets.

Included in the rare metals whose unstable supply is apprehended is the following: (1) elements whose reserves and quantity of production are extremely small, and whose ore-deposits are located in a handful of countries (platinum group elements, tungsten, heavy rare-earth elements), (2) elements produced only in extremely small amounts as by-products when other resources are mined, and therefore, of which it is very difficult to increase production to meet the needs (such as indium which is mostly produced as by-product of zinc).^[1][2]

In order for Japan, a resources-poor country, to continue valuing "monozukuri" (manufacturing), create new industry and maintain its position as an advanced industrial country in the future, it needs to alleviate the supply instability of rare metals and to heighten its level of rare metal resource security.

Furthermore, problem solving by development of new technology is believed to lead to big chances for creation for our industry.

The measures adoptable by public research institutions are the diversification of resource supply options through search for new ore-deposits, the development of resource-saving technologies and alternative material technologies and the buildup of recycling technology. Moreover, to suppress speculation, it is important to strive for dispatch of effectual information.

AIST is the only institution in Japan that is organizationally carrying out the above-mentioned research and development measures. Moreover, although the research done may not be intentionally on rare metals, a large number of researchers are engaged in technological development using the special characteristics of rare metals. However, previously, as many research units had been engaged in individual problems according to their own specialties, coordination and dispatch of information necessary for tackling the rare metal problem were not enough.

The rare metal task force was organized in 2006 to actively tackle the rare metal problem by promoting field-integrating research topics which straddle several research units in our institute. Figure 3 shows an image of an integrated research that the rare metal task force is aiming for.