Home / English Posts / XRD Analysis of some Metals

XRD Analysis of some Metals

We propose in this Post the XRD analysis of some metals.

Gold

Gold is a chemical element with symbol Au (from Latin: aurum) and atomic number 79. In its purest form, it is a bright, slightly reddish yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal. It is one of the least reactive chemical elements and is solid under standard conditions.
The sample examined by XRD technique consists of a quartz crystal (used in oscillators) with the surfaces partially covered by a layer of gold. The crystalline system is cubic fcc.

For the Bragg reflection of gold we fill in the following table using the following formulas :

  • λ = 0.1542 nm
  • d = λ / 2senθ
hkl d(nm)
 111  37.67  0.2388

The interplanar distance obtained is close to the exact value which results to be 0.235 nm.

Aluminium

Aluminium or aluminum is a chemical element with symbol Al and atomic number 13. It is a silvery-white, soft, nonmagnetic and ductile metal in the boron group. By mass, aluminium makes up about 8% of the Earth’s crust; it is the third most abundant element after oxygen and silicon.
The sample examined by XRD technique consists of a fine powder sample pressed inside a plastic ring. The crystalline system is cubic fcc.

For the Bragg reflection of aluminium we fill in the following table using the following formulas :

  • λ = 0.1542 nm
  • d = λ / 2senθ
hkl d(nm)
 111  38,33  0,2348
 200  44,5  0,2036

The interplanar distance obtained is close to the exact value which results to be 0,2025 nm.
The peaks are rather broadened, this can be likely due to the little size of the aluminium powder particles.

Beryllium

Beryllium is a chemical element with symbol Be and atomic number 4. It is a relatively rare element in the universe. It is a divalent element which occurs naturally only in combination with other elements in minerals. As a free element it is a steel-gray, strong, lightweight and brittle alkaline earth metal. Because of its low density and atomic mass, beryllium is relatively transparent to X-rays and other forms of ionizing radiation; therefore, it is the most common window material for X-ray equipment and components of particle detectors.
The sample examined by XRD technique consists of a circular plate. The crystalline system is hcp (hexagonal close-packed).

For the Bragg reflection of beryllium we fill in the following table using the following formulas :

  • λ = 0.1542 nm
  • d = λ / 2senθ
hkl d(nm)
 002  50,5  0,181

The interplanar distance obtained is close to the exact value which results to be (double the measured value) 0,358 nm.

Magnesium

Magnesium is a chemical element with symbol Mg and atomic number 12. It is a shiny gray solid which bears a close physical resemblance to the other five elements in the second column (group 2, or alkaline earth metals) of the periodic table: all group 2 elements have the same electron configuration in the outer electron shell and a similar crystal structure.
The sample examined by XRD technique consists of a thin sheet. The crystalline system is hcp (hexagonal close-packed).

For the Bragg reflection of magnesium we fill in the following table using the following formulas :

  • λ = 0.1542 nm
  • d = λ / 2senθ
hkl d(nm)
 002  34,2  0,262

The interplanar distance obtained is close to the exact value which results to be (double the measured value) 0,521 nm.

Copper

Copper is a chemical element with symbol Cu (from Latin: cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity.
Copper, silver, and gold are in group 11 of the periodic table; these three metals have one s-orbital electron on top of a filled d-electron shell and are characterized by high ductility, and electrical and thermal conductivity. The filled d-shells in these elements contribute little to interatomic interactions, which are dominated by the s-electrons through metallic bonds. Unlike metals with incomplete d-shells, metallic bonds in copper are lacking a covalent character and are relatively weak. This observation explains the low hardness and high ductility of single crystals of copper. At the macroscopic scale, introduction of extended defects to the crystal lattice, such as grain boundaries, hinders flow of the material under applied stress, thereby increasing its hardness. For this reason, copper is usually supplied in a fine-grained polycrystalline form, which has greater strength than monocrystalline forms.
The crystal structure is face-centered cubic (fcc).

For the Bragg reflection of copper we fill in the following table using the following formulas :

  • λ = 0.1542 nm
  • d = λ / 2senθ
hkl d(nm)
 200  50,33  0,181

The interplanar distance obtained is close to the exact value which results to be (double the measured value) 0,361 nm.

Tantalum

Tantalum is a chemical element with symbol Ta and atomic number 73. Tantalum is a rare, hard, blue-gray, lustrous transition metal that is highly corrosion-resistant.
Tantalum exists in two crystalline phases, alpha and beta. The alpha phase is relatively ductile and soft; it has body-centered cubic structure (lattice constant a = 0.33058 nm). The beta phase is hard and brittle; its crystal symmetry is tetragonal (a = 1.0194 nm, c = 0.5313 nm). The beta phase is metastable and converts to the alpha phase upon heating to 750–775 °C.
Bulk tantalum is almost entirely alpha phase, and the beta phase usually exists as thin films.

For the Bragg reflection of tantalum we fill in the following table using the following formulas :

  • λ = 0.1542 nm
  • d = λ / 2senθ
hkl d(nm)
 200  55,5  0,166

The interplanar distance obtained is close to the exact value which results to be (double the measured value) 0,331 nm.

Check Also

XRD su Fibre

Introduzione La diffrazione da fibra è una branca della tecnica della diffrazione, una tecnica in cui …