---
title: "Ferromagnetic versus antiferromagnetic materials"
subject: "Electrical Engineering Material"
chapter: 4
key: "semester_3/electrical_engineering_material:ferro-vs-antiferromagnetic"
source: https://www.bctengineer.com/q/semester_3/electrical_engineering_material/ferro-vs-antiferromagnetic
site: BCT Engineering
---

# Ferromagnetic versus antiferromagnetic materials

Electrical Engineering Material · Chapter 4: Magnetic Materials

- Asked in: 2076 Chaitra, 4+1 marks
- Video: [Types of Magnetic Materials and BH Curve (Part1) | Basic Electrical Engineering | S Chand Academy](https://www.youtube.com/watch?v=c6vyraPzv14) — S Chand Academy
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_3/electrical_engineering_material/ferro-vs-antiferromagnetic
- Whole chapter: https://www.bctengineer.com/md/semester_3/electrical_engineering_material/chapter-4

## Question

Distinguish between ferromagnetic and anti-ferromagnetic materials. Give an example for each class of material.

## Short answer

Ferromagnetic materials have parallel neighbouring moments, large net magnetization, high susceptibility, and exhibit hysteresis below Curie temperature; example: iron. Antiferromagnetic materials have antiparallel equal moments with zero net magnetization, small susceptibility, and a Néel temperature above which paramagnetic; example: MnO.

## Answer

| Point | Ferromagnetic | Antiferromagnetic |
|---|---|---|
| Spin arrangement | Neighbouring moments parallel | Neighbouring moments antiparallel, equal |
| Exchange interaction | Positive | Negative |
| Net spontaneous magnetization | Large | Zero |
| Susceptibility $\chi$ | Very large ($10^2$–$10^5$) | Small, positive |
| Critical temperature | Curie temperature $T_C$ | Néel temperature $T_N$ |
| Above critical temp. | $\chi = C/(T - T_C)$ | $\chi = C/(T + \theta)$ |
| Below critical temp. | $\chi$ very large, falls with $T$ | $\chi$ increases with $T$ up to $T_N$ |
| Domains and hysteresis | Present | Absent |

```text
 Ferro:      ^  ^  ^  ^  ^
 Antiferro:  ^  v  ^  v  ^
```

#### Examples
- **Ferromagnetic**: iron (Fe), also Co, Ni.
- **Antiferromagnetic**: manganese oxide (MnO), also FeO, NiO, Cr.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Neighbouring moments in an antiferromagnet are:
   A. Antiparallel and equal, so net magnetization is zero
   B. Parallel, giving large magnetization
   C. Antiparallel and unequal
   D. Random with no exchange interaction
   Answer: A. Equal antiparallel moments cancel. (Key point: Spin arrangement)

2. What is the sign of the exchange interaction in ferro and antiferromagnetic materials?
   A. Negative in ferro, positive in antiferro
   B. Positive in ferro, negative in antiferro
   C. Positive in both
   D. Negative in both
   Answer: B. Positive exchange aligns spins parallel; negative aligns them antiparallel. (Key point: Exchange sign)

3. What are the critical temperatures of ferro and antiferromagnetic materials called?
   A. Néel for ferro, Curie for antiferro
   B. Both are called Curie temperature only
   C. Curie temperature Tc and Néel temperature TN respectively
   D. Debye temperature for both
   Answer: C. Ferro: Curie temperature; antiferro: Néel temperature. (Key point: Critical temperature)

4. Which pair is correct?
   A. Ferro: MnO; Antiferro: Fe
   B. Both show hysteresis; examples Fe and Co
   C. Ferro: no hysteresis; Antiferro: hysteresis
   D. Ferro: Fe, with domains and hysteresis; Antiferro: MnO, with no domains or hysteresis
   Answer: D. Fe is ferromagnetic with hysteresis; MnO is antiferromagnetic without domains or hysteresis. (Key point: Examples and hysteresis)

## Related in Electrical Engineering Material

- [Ferrimagnetic versus antiferromagnetic materials](https://www.bctengineer.com/question.md?key=semester_3%2Felectrical_engineering_material%3Aferri-vs-antiferromagnetic) — Electrical Engineering Material, chapter 4
- [Ferrimagnetic versus ferromagnetic materials](https://www.bctengineer.com/question.md?key=semester_3%2Felectrical_engineering_material%3Aferri-vs-ferromagnetic) — Electrical Engineering Material, chapter 4
- [Ferro vs antiferromagnetic; magnetostriction](https://www.bctengineer.com/question.md?key=semester_3%2Felectrical_engineering_material%3Aantiferro-magnetostriction) — Electrical Engineering Material, chapter 4

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