introduction

This Web-Page will offer some practically fundamental materials of solid, including valuable material on process and transport theory. At first, some fundamental material of atoms and chemical bonds are introduced. At second, some physical and chemical properties of crystals are described. At third, thermal, electric, magnetic, and optical properties of solid are introduced. At last, some interersting solid, such as superconductor, will be introduced.

a)	Assuming that an electron moves around on its own axis, it seems natural for us to estimate the center of electron particle at the super-strongly magnetic field. Such strong magnetic field has not been found on the center of electron. To underestimate the center at the small field implies that electron does not turn around its own axis.
b)	Rough spin-spin interaction strength may be determined by use of Helium atom. The interaction strength is larger than 2eV. This interaction strength is large enough to influence the electron configuration of the heavier atom(ca. Y, Zr, Nb, Hf, Ta etc.). We can not find in all transition metal atoms the electron configurations influenced by electron-electron interactions.
c)	Electron spin was discovered by Stern-Gerlach. But, it must be remarked that his discovery is based on the experiments using silver atoms but not on the experiments using electron only. An electron of atom turns around the nucleus. We can not estimate the magnetic field yielded by the revolution of electron at zero, even if we take into account of our well-known spin. A silver atom at the ground state has the electron configuration with electron spin 1/2. It may be allowed to deduce the following mechanism different from his spin-mechanism; his experimental results are caused by both kinds of revolution-directions. Can you stress that Stern-Gerlach experiments is explained by the magnetic property, yielded by self-rotation of electron particle, but not by the property of atomic orbital observed as Zeeman's effect ?

These three problems are too important for us to declare that the conventional definition of electron spin is trustworthy.
Electrons on atomic orbitals give an atom a kind of magnetic property. However, we know that a magnetic field depends on space. According to our well-known electromagnetism, it seems very mysterious and dangerous to estimate the magnetic property of atom at a kind of eigen-value (spin) independent from the space( see Atom).
Both directions( self-rotation and revolution-direction of electron) must be determined by use of 4-dimensional axes, including time. But, even if we adopt the conventional definition of electron spin, we can experimentally observe each spin quantum state of electron in an atom under our observed time-axis. This experimental fact implies that each spin-state of electron in an atom at the ground state may be interpreted by use of one time-axis( our observable time axis) only, and, in order words, by taking into account of the revolution-direction. In order to avoid from the above difficulty, it may be allowed to introduce the new concept of electron spin as follows:

The magnetic property of electron is deduced through examining the revolution- direction of electron on an atomic orbital. The new definition of electron-spin is described as follows:

Two kinds of electron-spins, represented as +1/2, -1/2, respectively, indicate the following two kinds of revolutions of electron in atom, respectively; clockwise and anti-clockwise.
This new proposal of electron-spin indicates that the spin is defined as the parameter dependent on both space and time.

All of these above problems may be solved easily by use of my new definition. My new proposal might make it more easier than now to interpret some chemical bonds including a metallic bond. Also, my proposal will clarify the reason why the statistical distribution function of electrons in solid is represented by Fermi's distribution function. I do not like some roundabout explanations decorated with many genius so much. The definition of electron spin must be very simple.

a)	A statistical interpretation must be deduced by the research based on the large amount of statistical data. Nothing except properties of an atom and a molecule are regarded as statistical data for solid state physics and chemistry. Then, the lattice parameters are not. It is correct to state that X-ray pattern makes it possible to confirm the periodical arrangements of atoms in crystal. But, it must be noted that the microscopic properties of each atom do not include any lattice parameters.
b)	Free electron model guides us to the idea that conduction electrons interact attractively with one another through interaction between electron-spins( Gerlach-Stern spin) much longer between electrons than the radius of elementary particle(electron). Assuming that the above interaction is probable, it seems reasonable for us to deduce that the short-range interactions between electrons adjacent to one another must exert a explicit influence upon the internal quantum state of the elementary particle. Regretfully, no such influence described above has been found. Then, we can not mention that the condensation of conduction electrons in solid appear through spin-spin interactions.
c)	Many experimental facts suggest explicitly that conduction electrons in solid are mobile. But, energy levels of conduction electrons in solid, deduced by use of the model, imply that each conduction electron contributes to the geometrical stabily of solid. The model can not simply and plainly explain why conduction electron can play both roles: the mobility and stabilization. The modern solid state physics and chemistry suggests that the aggregation of conduction electrons contributes to the geometrical stability of solid. But, if each energy level, deduced by use of free electron model, were comfortable to conduction electrons, we could easily find the process to the aggregation. It is very difficult to discover the process. It weights on my mind that each orbital of electron on the level can not experimentally be observed. The difficulty implies that each energy level, deduced by use of free electron model, is a kind of imaginary level figured by us.

It seems natural to deduce that conduction electrons without the destinations can go to the vacuum soon after. Many scientists might stress that conduction electrons is fastened in solid by electron-electron interactions.
Do you believe that a person can go round the world without food, drink, car-gasoline supply ? It may be allowed to compare 40000km journey for a person to the transfer for an electron from the edge of a metal wire to the other. Do you believe that a conduction electron can move from one edge of metal wire to the other without energy supply ? We must remark that both emitted and arrived electrons in solid are not always the same electron( ca. observation of current).We can not regard an electron as a peculiarly physical matter discriminated completely from another matters.
Assuming that conduction electrons are fastened by the condensation effect due to the electron-electron interactions, the stronger restraining energy than the ionization potential( energy to go electron away to the vacuum ) gives us the idea that these electrons move along these crystal orbitals only.
The above discussions suggest that there are more energetically preferable pathways for the transfer of electron than another. However, when we examine the effect, such as Joule effect appearing with electric current, we must take into account of collision with lattices and atomic nuclei. Why and how can such strongly restrained conduction electrons on crystal orbitals(free electron orbital) collide frequently with lattice or atomic nuclei ?
It seems impossible to find these answers in the concepts based on free electron model. A kind of loose coupling between electrons may be imaged in order to avoid from the above problem. Such coupling does not give us the answer to the question why conduction electrons are fastened in solid. The modern solid-state physics and chemistry based on the free electron model looks a kind of horoscopy.

It may be allowed to suggest from the experimental mobility of conduction electron that solid has a great amount of temporarily physical positions ( not a theoretical position) in it able to accept conduction electrons. Regretfully, the free electron model neglects completely the acceptably physical positions. Details, including the problem where are an acceptable position, are described in section chemical bond. You will find in the section that Fermi's energy level is determined through examining atomic orbitals in solid.
Conduction electrons are free from the geometrical direction. Assuming that an atom has the position, it seems reasonable to estimate from the electrostatic viewpoint that these conduction electrons can move to another atoms. The transfer yields the electron-deficient atom. The mutual electron transfers of electrons between physical positions( atomic orbitals) make atoms bind with one another. The over-electron-transfer makes a small part of electrons possible to go to another atoms.
The electrons contributing to the electric current must be a small part of total electrons evaluated from total atoms in solid. The resonant mutual electron transfer may make possible the long-range transfer of electron and the high-speed transfer.
This Page adopts the following proposal;
Solid has a great amount of temporarily physical positions in it able to accept conduction electrons. The mutual electron-transfer between atoms promotes the geometrical stability of solid.
My proposal means that the conduction electrons are not on the orbital deduced by use of the model, but are either on the atomic orbitals or orbital made by the linear combination of atomic orbital.
The detailed proposal including the production of conduction electron will be described in section Chemical Bond. My proposal will prove highly efficiently for understanding the processes and transports in solid, which will be described in each section(electric, thermal, etc..)).

It is the most important for me to create a new functional device, such as high-speed device, a superconductor with high-critical temprature, etc.. The modern solid-state physics and chemistry given up to date need too theoretical supports for me to take them in my tiny brain. Then, I discovered these two proposals, These two proposals made me very easy to understand many solid-state appearances, because these appearances can be explained without some complicated theoretical supports and with our experimental knowledges. However, these proposals have one important demerit; some appearances, such as electric conductivity, are explained by use of the mechanisms much different from our well-known mechanism. I have been annoyed with these differences. Some important appearances will be described in this Home Page.
Now, I believe that, in this Page, you will find solid-state physics and chemistry more understandable for you than ever.

Please send me your any suggestions and comments, if you find any practical viewpoints. Your comments will be put in this Page as possible as I can.