The "Invisible Magic" Inside an iPhone: The Secret of Rare Earth Functional Materials

When you pick up an iPhone 17 Pro and enjoy its dazzling screen, smooth touch feedback and clear night photos, you may not have thought that behind these high-tech experiences lies an "invisible magic" - rare earth functional materials. These unassuming materials, weighing only 0.1-0.2% of the iPhone (about 0.2-0.5 grams), determine the phone's performance and experience. Today, let's uncover which rare earth functional materials are in the iPhone, where they are used, and how "magical" they are!

Rare earth functional materials: small size, big role

Rare earth functional materials are compounds made from rare earth elements (17 kinds of metals, such as neodymium, europium, lanthanum, etc.). With their unique magnetic, luminescent and optical properties, they have become the "soul components" of smartphones. An iPhone 17 Pro mainly uses 5-6 kinds of rare earth functional materials, totaling about 0.2-0.5 grams of rare earth elements (equivalent to a grain of rice). Although the amount is small, they make the iPhone's screen more vivid, vibration more precise, and the lens clearer. Here is a "family photo" of these materials!

1. Neodymium-Iron-Boron Permanent Magnets: The "Power Core" of Vibration and Sound Quality

- Rare Earth Elements: Neodymium (Nd), Praseodymium (Pr), Dysprosium (Dy), Terbium (Tb)

- Usage: Approximately 0.15-0.3 grams (rare earth content: 0.05-0.1 grams)

- Applications:

  - Speakers: Neodymium-Iron-Boron (NdFeB) is the world's strongest permanent magnet, enabling the iPhone's speaker to produce powerful sound quality in a small volume. Whether listening to music or watching movies, the bass is rich and forceful.

  - Taptic Engine: The "click" sensation when you tap the screen and the vibration for notifications are all driven by precise feedback from NdFeB magnets. Dysprosium and terbium ensure the magnet remains stable at high temperatures.

  - Camera Focus Motor: Quick focusing and capturing clear night scenes rely on the movement of the lens driven by magnets.

- Little Secret: NdFeB accounts for 60-70% of the rare earth usage in iPhones, making it the "usage champion."

2. Rare earth phosphors: The "color tuner" of the screen

- Rare earth elements: Europium (Eu), Terbium (Tb), Yttrium (Y)

- Usage amount: Approximately 0.02 - 0.05 grams

- Where used: The backlight or luminescent layer of the display (OLED or LCD). Europium brings out vivid red, Terbium provides pure green, and Yttrium enhances the fluorescence efficiency, making the screen colors of the iPhone more vivid and with higher contrast, such as "Sunset Red" or "Forest Green" can be accurately reproduced.

- Secret tip: OLED screens use less phosphors than LCDs, but rare earths are still needed to ensure accurate colors. The reason your iPhone screen is "pleasing to the eyes" is all thanks to this tiny "color-tuning agent"!

3. Lanthanide optical glass: The "vision guardian" of lenses and screens

- Rare earth elements: Lanthanum (La), Cerium (Ce)

- Usage amount: Approximately 0.01 - 0.03 grams

- Where used:

  - Camera lenses: The three-camera system of iPhone 17 Pro (wide-angle, ultra-wide-angle, telephoto) uses lanthanum glass. Due to its high refractive index and low dispersion, it can reduce light scattering, making night scenes clearer and colors more realistic.

  - Display protection glass: Such as Ceramic Shield, which contains trace amounts of lanthanum, enhances anti-reflection performance and reduces glare.

- Secret tip: Lanthanide glass makes the lenses thinner but more powerful. It is the behind-the-scenes hero of the "black technology" of iPhone photography.

4. Cerium-based polishing powder: The "smooth magic" of screens and lenses

- Rare earth element: Cerium (Ce)

- Usage amount: Trace amount (<0.01 grams, used only for manufacturing)

- Where used: For polishing the screens of iPhones (such as Ceramic Shield) and camera lenses, achieving nanometer-level smoothness to ensure optical quality. The screen doesn't reflect light, and the lens captures images clearly. Cerium plays a crucial role!

- Secret tip: The polishing powder does not remain in the finished product, but it is indispensable during the production process and can be regarded as the "behind-the-scenes hero".

5. Rare Earth Doped Coatings: The "Guardian" of Durability and Clarity

- Rare Earth Elements: Yttrium (Y), Lanthanum (La)

- Dosage: Trace amounts (<0.01 grams)

- Where Used: Anti-reflective coatings and oil-repellent layers on screens and lenses, reducing glare and fingerprints, and enhancing durability.

- Secret: These coatings make the iPhone screen more scratch-resistant and always look "brand new".