The Curie temperature for cobalt is:
1388 K
Understanding the magnetic properties of materials is crucial in physics and engineering. One important property of ferromagnetic materials is their Curie temperature.
What is Curie Temperature?
The Curie temperature, often denoted as \( T_C \), is the critical temperature above which a ferromagnetic material loses its ferromagnetism and becomes paramagnetic. Below the Curie temperature, the magnetic dipoles within the material are aligned, leading to strong magnetic properties. Above the Curie temperature, thermal energy overcomes the forces that keep the dipoles aligned, and the material behaves like a paramagnetic substance, exhibiting only weak magnetism in the presence of an external magnetic field.
Curie Temperature of Cobalt
Cobalt (Co) is a common ferromagnetic material. Its Curie temperature is a specific value that determines its magnetic behavior at different temperatures.
Let's look at the provided options and the known value for the Curie temperature of cobalt:
- Option 1: 1043 K
- Option 2: 637 K
- Option 3: 3862 K
- Option 4: 1388 K
The established Curie temperature for cobalt is approximately 1388 K (or 1115 °C). This is significantly higher than that of iron (about 1043 K) or nickel (about 630 K).
| Material | Curie Temperature (K) |
|---|---|
| Iron (Fe) | \(\approx 1043\) |
| Cobalt (Co) | \(\approx 1388\) |
| Nickel (Ni) | \(\approx 630\) |
| Gadolinium (Gd) | \(\approx 293\) |
Comparing the known value with the given options, Option 4, 1388 K, matches the approximate Curie temperature for cobalt.
Selecting the Correct Curie Temperature for Cobalt
Based on experimental data and widely accepted material properties, the Curie temperature for cobalt is found to be around 1388 K. Therefore, among the given options, 1388 K is the correct value.
Revision Table: Key Magnetic Concepts
| Concept | Description |
|---|---|
| Ferromagnetism | Strong attraction to magnetic fields, permanent magnetization possible. Dipoles aligned spontaneously below \(T_C\). |
| Paramagnetism | Weak attraction to magnetic fields, temporary magnetization in external field. Dipoles randomly oriented, weak alignment in field. |
| Curie Temperature (\(T_C\)) | Temperature above which a material transitions from ferromagnetic to paramagnetic state. |
Additional Information on Cobalt Properties and Curie Temperature
Cobalt is a hard, brittle, silver-white metal. It is ferromagnetic, similar to iron and nickel. The high Curie temperature of cobalt makes it useful in applications where magnetic properties are required at relatively high temperatures, such as in certain types of magnets and magnetic recording media. Understanding the Curie temperature is vital for designing and utilizing magnetic materials effectively. The transition at the Curie temperature is a second-order phase transition.
Important Questions from Magnetism and Maxwell's Equations
- Which type of magnetic material is characterized by an induced magnetic moment that consistently opposes the applied external magnetic field, resulting in a small, negative volume magnetic susceptibility ($\chi_v$)?
A metallic rod when placed in strong magnetic field, aligns itself at right angles to the magnetic field. The nature of material is:
Identify which of the following expressions is not Maxwell’s equation for time-varying fields.
Which of the following materials is used for the generation of ultrasonic waves by using magnetostriction effect?
Ampere circuital law can be expressed as:
