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

# Ferrimagnetic versus ferromagnetic materials

Electrical Engineering Material · Chapter 4: Magnetic Materials

- Asked in: 2073 Chaitra, 6 marks
- Video: [Antiferromagnetic and Ferrimagnetic Materials](https://www.youtube.com/watch?v=zugNDYfJ_rc) — Dr. L. Sangeetha
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_3/electrical_engineering_material/ferri-vs-ferromagnetic
- Whole chapter: https://www.bctengineer.com/md/semester_3/electrical_engineering_material/chapter-4

## Question

Differentiate between ferrimagnetic and ferromagnetic materials.

## Short answer

Ferromagnetic materials have all atomic moments parallel, giving large net magnetization. Ferrimagnetic materials have two sublattices with antiparallel but unequal moments, resulting in a smaller net magnetization.

## Answer

**Ferromagnetic** materials have all atomic moments aligned parallel; **ferrimagnetic** materials have two sublattices whose moments are antiparallel but unequal, leaving a net moment.

```text
 Ferromagnetic:  ^  ^  ^  ^  ^
 Ferrimagnetic:  ^  v  ^  v  ^   (long ^, short v)
```

| Point | Ferromagnetic | Ferrimagnetic |
|---|---|---|
| Spin arrangement | All parallel | Antiparallel, unequal sublattices |
| Exchange interaction | Positive between neighbours | Negative between A and B sublattices |
| Net magnetization | Sum of moments (large) | Difference of sublattice moments (smaller) |
| Saturation flux density | High (Fe ≈ 2.1 T) | Lower (≈ 0.3–0.5 T) |
| Susceptibility | Very high ($10^2$–$10^5$) | High ($10$–$10^4$) |
| Nature of material | Metals and alloys | Ceramic oxides (ferrites) |
| Electrical resistivity | Low (~$10^{-7}$ Ω m) | Very high (1–$10^{6}$ Ω m) |
| Eddy-current loss | High, needs laminations | Very low |
| Frequency range | Power frequency (50 Hz to kHz) | kHz to GHz |
| Mechanical nature | Ductile, easy to roll into sheets | Hard, brittle, moulded and sintered |
| Critical temperature | Curie temperature $T_C$ (Fe 770 °C) | Curie (Néel) temperature, lower (100–600 °C) |
| Examples | Fe, Co, Ni, Si-steel, permalloy | Fe₃O₄, MnZn and NiZn ferrites, YIG |
| Uses | Power transformers, motors, generators | SMPS transformers, RF inductors, antenna rods, microwave isolators |

Both show domains, hysteresis, saturation and become paramagnetic above their critical temperature.

## Check yourself

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

1. How is net magnetization obtained in ferro vs ferrimagnetic materials?
   A. Ferro: sum of all moments; ferri: difference between sublattice moments
   B. Ferro: difference; ferri: sum
   C. Both: sum
   D. Both: zero
   Answer: A. Ferrimagnets have antiparallel unequal sublattices. (Key point: Net magnetization)

2. Which statement about resistivity is correct?
   A. Ferro metals have higher resistivity
   B. Ferrites (ferri) have very high resistivity; ferro metals have low resistivity
   C. Both are equal
   D. Ferrites are good conductors
   Answer: B. High resistivity gives low eddy loss in ferrites. (Key point: Resistivity)

3. Which frequency range suits each?
   A. Ferro: GHz; ferri: 50 Hz
   B. Both only at 50 Hz
   C. Ferro: power frequency; ferri: kHz to GHz
   D. Ferro: microwave; ferri: DC only
   Answer: C. Ferrites are used in SMPS, RF and microwave devices. (Key point: Frequency use)

4. Compared with ferromagnets, ferrimagnets have:
   A. Higher saturation flux density
   B. Infinite saturation
   C. No saturation
   D. Lower saturation flux density
   Answer: D. Ferrite Bs is about 0.3 to 0.5 T versus about 2.1 T for Fe. (Key point: Saturation)

## Related in Electrical Engineering Material

- [Ferromagnetic versus antiferromagnetic materials](https://www.bctengineer.com/question.md?key=semester_3%2Felectrical_engineering_material%3Aferro-vs-antiferromagnetic) — Electrical Engineering Material, chapter 4
- [Ferrimagnetic versus antiferromagnetic materials](https://www.bctengineer.com/question.md?key=semester_3%2Felectrical_engineering_material%3Aferri-vs-antiferromagnetic) — Electrical Engineering Material, chapter 4
- [Magnetic moments; ferro vs ferrimagnetic materials](https://www.bctengineer.com/question.md?key=semester_3%2Felectrical_engineering_material%3Adipole-moment-ferro-ferri) — Electrical Engineering Material, chapter 4
- [Classification by susceptibility; ferro vs ferrimagnetic](https://www.bctengineer.com/question.md?key=semester_3%2Felectrical_engineering_material%3Aclassify-susceptibility-ferro-ferri) — Electrical Engineering Material, chapter 4

## Related in other subjects

- [Soft versus hard magnetic materials](https://www.bctengineer.com/question.md?key=semester_5%2Felectric_machine_design%3Asoft-hard-magnetic-materials) — Electric Machine Design, chapter 1, asked 5×